Pokemon Red when it was fresh and new. I think that it was before Gen II came out as I remember seeing the commercial for it a lot later. But Gen I and Gen II games were mostly borrowed. My first game was Ruby. I bought GBA just so I could play it.
The story's like this: In 1999/2000, I visited my cousins and they had this awesome game. I borrowed it from them for a few days and I...erased their save file because I had no clue what I was doing since the game was in French, and I don't speak French. I fell in love with the game (and soon afterwards with the whole RPG genre), but couldn't beat it because of the language barrier. I didn't know that I could catch Pokemon, and I didn't know about Cut. So no Lt. Surge for me. I kinda forgot that I actually played the game first, and then started watching the show. Later the show aired and everybody played the games, so I had the luck to borrow games from my friends. My neighbor bought Gold when it came out and I was hooked. The reaction was mostly like everyone's. Omgkanto, omgred.
I can't really remember when exactly I bought Ruby, but it was probably a year or two after the release. After seeing the Advanced season, I was really surprised seeing May in the game and I usually played as her. Sadly, that's the only Pokemon game I bought, until few days ago. I've completed my GB/C main collection (half borrowed and forgotten, half bought of an auction for lulzy price). Now I can work on the GBA collection, but it'll be a bit difficult since I don't see Gen III offers on the sites I visit.
Thanks to emulators, I got to play Fire Red and Leaf Green, but thanks to my old computer, I didn't get to play Gen IV. I played Diamond a bit and that's it. When I bought a DS, I jumped straight to Gen V. I started Soul Silver on it, but kinda lost interest due to Gen V. I'll finish it soon though.