Adept's a lot easier to play in ME2 from what my girlfriend's told me. That's her favorite class, I honestly haven't really played Adept much in either game.
My fave is Infiltrator. Sentinel and Vanguard are tied for second. Vanguard for the sheer power, and Sentinel for the extreme tankiness due to Tech Armor.
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Gamertag-Murphiroth
Pokemon Black-1978-9490-1161