If you are just starting airsoft i would highly recommend an aeg, (airsoft electric gun) but if you are pro and experienced, a trained camouflaged sniper is the best, an invisible predator. However it does depend on the user of the gun. If you are asking performance wise then g&g makes the best airsoft guns on the market. (currently in the US)
Nerf gun
You can do target practice, or you can have an airsoft war with your friends! I have been in an airsoft war and it is very fun!
The best airsoft gun you could get for $150 would probably be an Aftermath gun, but you could get a JG M4 or M16 for under $150
The one you can afford
if you are tight in budget i suggest you buy the A&K M249 Para
None. There is no first airsoft war. Unknown original.
I say twin ozez are the best cheap airsoft guns
dont get that gun walmart has the best beginer guns
it depends on what cheap is to you
Definitely Nerf.
www.shortyusa.com
The best way - go to near airsoft workshop, give them money and tell what do you want. If you decide to modify airsoft gun by yourself - be warned, this may ruin your gun and even be dangerous to your health.