Fallout (at least from my experience, only played 3 and New Vegas) plays very much like the Elder Scrolls - unsurprising, as it's from the same studio - except instead of a medieval fantasy world, you're in the post-apocalyptic ruins of a world where the Cold War ended with a bang. The outside world is called a wasteland for a reason - they do a good job of making it feel really lonely, with isolated groups just beginning to properly reach out to each other. The combat is something I haven't seen much of elsewhere - you can use guns like a shooter, or melee weapons like the Elder Scrolls, or you can pause and issue combat commands like KotOR - it's not the most challenging combat, but that's because the emphasis is really on the environment and the storytelling. You really should check them out.
Also perhaps worth checking out is Alpha Protocol. People have very mixed opinions on this game, but I enjoyed it - as is the case with most of Obsidian Entertainment's products, it's flawed, but if you can look past those flaws, it does some really awesome stuff, usually in the storytelling and plot department. It's essentially a Spy RPG. The gameplay is not particularly good - if you play it like I did, you'll just sneak around knocking people out/picking them off with your silenced pistol. Where it shines is in the dialogue system - it's got a timed dialogue wheel, much like the Walking Dead - you can mess with it if you need to (and sometimes you will - you have to make very tricky decisions under pressure, such as whether to execute someone or not, or whether someone is reaching for their gun or just making an innocent gesture) And unlike with ME or DA, sometimes you can screw up/succeed with your dialogue choices, allowing you to sometimes bypass fights, or trigger them, or whatever. And the story can be run, and end, in so many different ways - some of which are really quite surprising (my ending threw some awesome twists my way, that's for sure). You might like it, you might not, but I'd advise checking it out.
