2nd gen is and always will be my favorite gen of the three I played.
Let me tell you about my experience with 3rd, though. I had tried it when it first came out and disliked it pretty much immediately, so I assumed that all the people who said it was the worst gen were spot on the money, and never finished it.
Then several years later I picked it up again and whoa, it was super fun! It reminded me just how much I love Pokemon. So yeah, I like 3rd gen.