I never finished the third one. I kinda want to revisit and finish the trilogy sometime. I remember enjoying the RPG elements but looking back on it, it really glorifies the military, you're basically the space CIA if I remember right. You also team up with Garrus, who's a vigilante cop and the Space Fascist in the third one, whose genocidal racism is treated like "haha he's like your racist grampa lol".
Playing ME2 currently and I think it's great with the exception of planet scanning mechanic. Can't decide on the optimal level 30 soldier build.