I don't think there are many such games. I guess Doom 3 kind of counts. I mean, I did like it even originally, but I couldn't get into it properly. Then when I played it later, I could. Something just clicked better. Another example is the Ratchet & Clank series, which I found fairly bland when I played it originally, but when I tried again last year, it was actually pretty fun. I mean, I didn't dislike it or anything in the first place, but I just didn't particularly like it either. There might be others as well, but that's all I can think of right now.
I also strongly suspect that the Paradox grand strategy games would be a good fit in this category if I had the time to play them. I've tried them in the past but haven't had the time to really learn them, so I haven't got into them - but I really suspect I would, had I the time. I'm not sure if that really counts in the spirit of this thread though...







