Fallout New Vegas + DLC, Love Fallout New Vegas, There are so many quests that have massive impact on the ending packed with choices and great characters, the story is really good and base on your choices essentially you decide which factions live or die and which side will win the war. You will meet some great personalities and see cool and crazy things in your Fallout NV travels.
Fallout 3 - Not as good as new vegas and lacks the same depth and choice impact but quite a different game set in a darker setting in a region more effected by the Nuclear war, but still a very good game.
Dragon Age Origins - Better on PC due to controls but still playable once you get use to it on console, If you enjoy the fantasy setting and choice in games I would recommend giving this one a go.
Alpha Protocol - An espionage RPG, Although it's not everyones cup of tea and the game lacks in production value and polish at times it still is a really fun game, The way you play is entirely up to you and how you upgrade your character and the story seems initially generic but get's a lot better later on, depending on what you do and the order in which you do it your likely to have a wildy different experience than others, some may betray you some may die.
The Mass Effect Trilogy - Although losing most of it's RPG elements in the second game it's really worth giving these games a go. No game has given me such a great bond between the characters, where I actually really care a about what happens to them and such emotional impact from events taken place, the choice impact isn't as great as it seems with shortcuts taken in ME3 causing a lot of decisions from ME1+2 to boil down to very little but it still is a brilliant game series with fun action packed gameplay an and has fascinating story and universe.
Also Martin Sheen Plays a prominent role in the second and third games, so that's always awesome.
Note: Leviathan DLC and Extended Cut are an absolute must to enjoy Mass Effect 3's Ending.
Hope this helped.