So far I've been playing with Overload, Sentry, Incinerate on an Engineer/Infiltrator with a sniper and pistol.
I'm really interested in trying out Biotics or Combat if anyone has any experience playing with those.
What are some fun weapons you've discovered?
Personally I'm overwhelmed by the choices and wish there was a training room where you could test out all the different weapons available. I was disappointed by the avenger assault rifle in this game, which is usually my classic favorite. I found that the old trilogy was mostly a medium range game being such a narrow corridor shooter usually. However this time around I find I'm usually long range or up close in melee/pistol engagement.
The mods for weapons and armor are also really cool! There is even a mod that turns the weapons back into Original Mass Effect style heat sinks. Pretty neat!