Re: Pokemon fans: a question.
The nice thing about Pokemon is you can start basically with any of the main games and be perfectly fine. The game explains new things to you as they come up (I think nearly every old school Pokemon player has a moment when they reach that part in each game when an NPC goes to teach you how to catch a Pokemon and you find yourself yelling "I know how to catch a damn Pokemon, just give me the pokeballs already!"). If you're at all worried about being a bit overwhelmed I'd probably suggest starting with Black and White because it doesn't have quite as many new shiny bits in it, plus for the main game you can only catch Pokemon from that region so there's not as many thrown at you for you to try and remember.

(Also funny that you mention Shin Megami Tensei, because I was once trying to explain the battle mechanics with the demons in SMT to someone and ended up with "It's a little like Pokemon, but instead of Pikachu you use Satan.")