The problem is that many of these buying guides rely on poor research, lack of understanding on how airsoft guns operate (people that make the argument that airsoft barrel extensions muffle a considerable amount of sound... -_- ).
I've been playing airsoft for about three years spending most of my free time doing research on most everything in the airsoft world.
I'm hoping that this guide will strongly influence your decision on purchasing an AEG. This is my first instructable, so I'll do my best to effectively communicate my thoughts and ideas.
NOTE: This is in no way a guide for purchasing real guns, nor are any of my suggestions even viable for real weapon use. This guide is for airsoft only.
Step 1: What is an AEG? / A Noteable Avoidance
These are the most common skirmish worthy airsoft guns. They use battery power (along with gears and a motor) to propel 6mm plastic bb's. Excellent for Infantry, Assault, Defense, and pretty much every other position (If you're a sniper, then Spring airsoft guns may also be a viable alternative).
Avoid Walmart and Sports Authority:
TRUST ME. I've spent well over $500 on cheap airsofts that break and become useless, since you can't Frankenstein them together. It's well worth it to save the $100+ required for a decent AEG.
Step 2: Key Words to Look For In An AEG
Some AEG's are made with crappy plastic gearboxes. These WILL break very fast. ALSO magazines are somewhat difficult to come buy. Plastic gearboxes are very typical of Walmart and Sports Authority Airsoft guns. If the label/distributor doesn't tell you what kind of gearbox it has, IT IS PLASTIC. Metal gearboxes are the only kind that you should have in your AEG. The parts last MUCH longer and the internals can shoot faster and harder (though metal gearbox AEG's can be purposely modified to shoot slower and weaker) than those of their plastic counterparts.
TOKYO MARUI COMPATIBLE:
Tokyo Marui invented the AEG back in the 90's, thus most brands are compatible with them. Basically, if your airsoft gun is compatible with Tokyo Marui you can use the same magazines and parts (in case something breaks) as ANYONE else that has Tokyo Marui compatible parts (I can share my Tokyo Marui M4 magazines with my friend's M4 that uses Tokyo Marui magazines). By making sure your airsoft gun is Tokyo Marui compatible you are potentially saving yourself a ton of money.
Step 3: (Other) Things to Consider When Looking for an AEG
Besides Tokyo Marui Compatibility, certain models take certain magazines. For example, I have an airsoft M4. My (Tokyo Marui compatible) M4 can share magazines with other M4's, the SCAR-L, the L85, the M249, and other guns. I cannot share magazines with the AK47 or the G36 without physically modifying the AK47 or the G36 (Some companies make a conversion kit that allows you to use M4 magazines) to accept only M4 magazines and no other. This is a huge deciding factor perhaps not initially, but as you continue to play the sport when it turns from 2 vs. 2 into 15 vs. 15.
Everybody loves the durability of metal bodied airsoft guns (as opposed to plastic bodies), but metal is heavy. Let's say for example, 7 pounds. 7 punds gets very heavy after a long day of playing especially when it is hot outside. Many AEG's that use plastic bodies use high quality plastics/ABS/and possibly Polymer. If you ever decided to trade that plastic body for a metal one, it will typically run you $50-100 for a metal body.
CQB (Close Quarters Battle) vs. Field (Pretty much anything that isn't close quarters)
Shorter barrel and stock lengths are typical of CQB environments. Longer barrels and stocks are typical of field environments. If you're just starting out you probably don't know whether you want short or long. My best advice to you would be to buy a standard length Airsoft Gun. If you wish to modify it later on It's not horribly expensive, plus you can sell your unused parts for money.
Unlike real firearms, different outer barrel lengths have a somewhat little effect on accuracy. Inner barrels (which are discussed later) do have an effect.
Step 4: Great Starting (Emphasis on "starting") Brands
They're the Lexus of airsoft guns mainly because they're typically more expensive (brand new), BUT they are of excellent quality (there's a reason airsoft guns are "Tokyo Marui compatible"). You could possibly use a Tokyo Marui AEG for years without ever having to maintain it (do not try this).
The Toyota of Airsoft guns. High quality airsoft guns, mostly rebrands of chinese AEG's but strict quality control makes them great. ALSO they are America based, so if there's ever a problem it should be easier to talk with them.
JG (Jing Gong) or Golden Bow:
The Scion of Airsoft Guns (FYI Scion is made by Toyota). Lower priced but typically just as good as Echo 1. Every once in a while you'll see someone with a factory defect issue, but I have only heard of one or two cases. GREAT affordability, though some of the metals in their guns are cheap metals (potentially rust can form). Also, you're pretty much screwed when it comes to manufacturer warranties.
Step 5: Brands to Avoid (as a beginner)
No name brands:
This one's a given. No warranty, bad idea to spend $100+ here.
NOTE: With the following brands these are only things that I have heard, I may be wrong, but throughout all the forums I've read, and watching all those Youtube airsoft reviews, this is what I've stumbled upon. Try to argue with me and I won't respond. ;)
ICS Also Known As TSD:
Their compatibility with other brands is questionable. I've heard that other brand magazines don't always feed into ICS airsoft guns properly. Also, ICS isn't 100% Tokyo Marui compatible, meaning that in order to install say, a new stock, you would have to buy an adapter piece to work with other brand stocks. The quality is supposedly excellent, but the downsides weigh a bit too heavy.
Infamous for crappy workmanship, magazine incompatibility (sometimes) and high prices. Found at Walmart and Sports Authority.
They are a top of the line brand, but I BELIEVE I heard about magazine compatibility issues, that's the only "no no" that I have for them, if you don't mind buying strictly KWA mags, then it's no problem. Other than that they are a great quality top of the line brand.
Step 6: My Personal Advice and Choice
The M4. There are plenty of variations which you can buy that use all the same parts.
My best advice to you would be to buy a standard length M4 with a Crane stock (the battery will go in the crane stock in order to keep the electrical wiring in the rear). Basically, if you don't get an airsoft gun with wiring in the rear, you'll have to re-wire the gearbox if you wanted a fixed (not adjustable) rear stock (usually for a larger battery). M4's are quite abundant at airsoft meets, making magazines plentiful and spare parts viable (in case you can buy them from other players). You can also see various accessories that you may want to mount on your own personal M4.
If you don't go for M4's, then AK47's would be the second most common airsoft guns, followed by MP5's, G36's (no particular order).
Step 7: Upgrades, Accessories, and Extras
You've bought your airsoft gun and now you want to make it awesome before your first game, or you've been playing with it and have decided that you want to customize it.
Whatever airsoft gun you decide to get, the first things that you'll want to buy are:
1. Smart charger - You're batteries WILL get damaged (worse case scenario: catching on fire/exploding) if you accidentally overcharge them. This will help.
2. Extra Battery - No one likes losing a game because of technical foul ups. Battery changes midgame are common. Getting a more powerful battery i.e. a 9.6 volt battery compared to a standard 8.4 volt battery will up your rate of fire. Getting a larger battery i.e. moving from 1300maH to 3000maH will drastically change the life of the battery (the higher the maH, the longer it lasts= the more shots you can get out of your airsoft gun). This is the #1 upgrade you can do to your airsoft gun.
NOTE: Li-Po batteries are becoming quite popular in the world of airsoft, but as a beginner it's unnecessary (there are extra precautions in addition to those of regular NiCd or NiMH batteries) LiPo's have a faster rate of fire, but in having a faster rate of fire your airsoft gun's internal parts will wear out sooner. Also you need a new charger and you have to be careful where you put them or they explode, they're expensive... Too many drawbacks and precautions for the new kid.
3. Tightbore barrel - 6.03-6.05 is a safe diameter. Any smaller and a speck of dirt will kill your airsoft; any bigger than 6.05 and the accuracy and FPS of your gun will suffer. This is the second best upgrade you can give your airsoft gun.
4. Extra magazines (at least 1) - You're just starting out so you don't know exactly how much ammo you will use per game. Better safe than sorry. One 85 round mid-capacity plastic magazine is about $10. Not bad for an extra mag. One 300 round high capacity magazine runs about $40.
Step 8: Go Out There and Have Fun
If you don't lose you can't possibly expect to get better.