I enjoyed using a sniper rifle as a Soldier in ME2/3 (though not as much as I'm enjoying it in ME1 with all those huge, open environments), but I don't like it being my main weapon. However, since I'm replaying, I want to do something different.
I wasn't really interested in any other class, until I experimented with some (in cut-down form) in ME3's multiplayer. My first play through all three game was as a male Soldier, and lots of fun was had. I'm currently replaying ME1, this time as a female Shepard (and an Infiltrator).
