Okay lets go:
Android - not bad.true , he has huge health and carry weight , but, lets be fair,there semes to be more food around him then anywhere.His speed is nothing compared to my fav, and he uses battery to fast.Add up with flash-light and laser,you'd be dead in a minute.still, he's not that bad.
Human - reliable. The basic and commonly used fighter. I tell 'ya, he hardly stands a chance in The Hive , though.I like him, but he's nothin' like my fav.
Psiconc - my fav's runner-up.I'll tell you, if that guy used some more health, he'd the fav of the game. Allmost PERFECT on easy.
Alien - you guessed it - she's my fav. Thats right, a she.Her speed and strength add up to half-invincibility, plus very good with night-sight. I love to sneak up and kill 'em. PLUS,you can get in to some planet wide warfare with your on brood.Definetly the best by me.