My first Pokemon game was Emerald. I played it quite a bit, although I never got past Slateport. I actually accidentally released my starter, since I also accidentally put him in the PC, and being the button masher I think I was, I always hit "deposit" and never "withdraw", meaning I couldn't retrieve him. I saw the "release" button and thought, "Oh, hey does it mean release it from the PC back into my party? Great!" and then proceeded to reset my game after I saw it slowly fade away.
My favorite is, unsurprisingly, BW and B2W2. I'm actually in the process of selecting my favorite of the two right now, by replaying them both. Overall, I just find them to be extremely enjoyable games, both gameplay-wise and, of course, story-wise.