Bioware knows how to make a good RPG, and this game is no different. While it has the third person shooter element, the core of this game is RPG with its story adaptable to your choices and NPC interactions.
You might hear a lot of people complaining about the ending (I won't spoil it for you). However, it's a product of it being "the cool thing" to do. Just as Call of Duty built steam once, Portal became the greatest thing under the sun, etc. etc., there's a mob mentality about the ending being unsatisfactory. I will disagree with this and say that if you put a little of your own thought into the ending, it was done well.
The combat element of this game was easy to pick up and enjoyable. The ability to take cover, run, and roll with one button was a great move, and made the fiercest firefights on Insanity Mode more manageable. The aiming and power buttons were also satisfactory.
Bioware knows how to make a game have a life of its own. Much as they did with Dragon Age (if you've played it), they added a lot of "background noise" with NPCs chatting amongst themselves, often telling stories that you sometimes stop just to listen to. The dialogue and voice acting throughout the game is also very enjoyable, and keeps you focused on the story and on the edge of your seat.
Bioware also continues to be one of the leaders in the gaming industry for breaking down the homosexuality barrier, as they have a few homosexuals (both male and female) throughout the game, and give gamers the option through dialogue and choices to be homosexuals. While it's not something I have an interest in, it is nice to see them include this to appeal to all gamers out there.