If you're going to import to ME2 I would try the Sentinel. The ME2 Sentinel is great fun. Very hard to kill and the only class in the game with powers effective against all armour types, so you can have much more fun with your bonus powers and choice of companions.
That said, the Adept in ME1 is very fun and silly effective, especially if you want to focus on using your biotics to deal damage or toss people around. Maxed out biotic push with the nemesis class bonus can one shot just about anything, and will cool down fast enough to be used every fight. Also, while singularity damage might be negligible having two crowd control powers really helps in some fights, and tossing enemies into the sky team rocket style never gets old.
Also, it's purely cosmetic but the Adept (and the Vanguard I think) get nifty purple biotic barriers in ME2 instead of blue shields.