Ahh, how much of my life was given to Pokemon...
Between me and my brothers, we have every single Pokemon gameboy game, except for the new Mystery Dungeon and Ranger. The only ones I really spent a lot of time on were Silver, Fire and Pearl. Fire, because I like the original pokedexes (Kanto+Johto) better than the third (Hoenn). And Pearl, because I could play with my Fire team again. And Wifi!
My only year in high school was filled with Pearl Wifi battles. No one could defeat my team of Mewtwos!
There's a new one launching in March, the Platinum version. It centers around Giratina. But really, he just looks like a giant Sir Krawlie made out of roughly hewn tin plates. The new pokemon and legendaries are ridiculous. But, I have to get it... Pokemon is a poison. I don't think these games will ever stop selling.
(Though if they want to make a really good one, they should go back to the Mewtwo/Mew/Team Rocket plots.)