[Bellerophon]

To give a fair recommendation, first I'd need to know your budget, secondly I'd need to know if you prefer gas or electric airsoft guns. A very brief summary:

Electric:
- generally less expensive
- rarely needs maintenance (though regular maintenance is highly recommended)
- works in most weather
- as smaller guns usually can't fit a regular sized battery, battery life can be a problem in electric SMGs
- relatively slow trigger response unless extensively modified

Gas:
- generally more expensive, mags especially so
- high maintenance (usually easier to maintain though, only mechanical knowledge required)
- fast trigger response, though the response and rate of fire slow down substantially after periods of rapid firing due to cooldown
- blowback is very fun
- usually does not work in cold weather