Games: Gold, Silver and Crystal
My absolute favorite Pokemon game of all time is Gold version (as well as its remake HeartGold). Don't get me wrong, Generation I was amazing and had a lot going for it, but looking back it kinda feels like it was rushed and they could've done so much more. Gen II fulfilled a lot of these wants for me.
I ended up getting both Gold and Silver versions for Christmas, and I chose Gold to start off. I was immediately hooked, and I can imagine I logged more hours into that game than I ever had before with any others. Keeping with my fire type choice from Gen I, Cyndaquil became my new partner and we made our way through the Johto region.
I honestly think this may have been one of my favorite sets of Gym Leaders, with Whitney, Chuck, and Claire giving me more of a challenge than many of the others I've faced over the years. Lance was a cool Champion too, and it was neat to get to battle alongside him to take down Team Rocket. I've already discussed why I like the rival Silver, and he's easily the best one in the series so far.
At the end of the Pokemon League challenge, you are given the opportunity to explore the Kanto region (from Gen I), 3 years after the events of the first games. It was great to see all the changes and battle old favorite trainers again.
This is the game I would recommend for you whether you're a first time player or returning to the franchise. It's really hard to go wrong with it!
Favorite Pokemon from this Generation:
Typhlosion, Tyranitar, Feraligatr, Scizor, Steelix, Kingdra, Crobat and Umbreon.
Team I used my first playthrough:
Typhlosion and Umbreon are the only two I remember. I've played this one so much!