I've contemplated buying Ranger, actually, though I think I'd prefer to get Battonage, when that comes out in the UK. I'm also contemplating purchasing Pokemon Link, because it looks like an interesting little puzzle game, and I'm quite fond of puzzle games, with the exception of Puzzle League, which I believe was for the N64, wasn't it?
Anyway, after I complete a Pokemon game, I usually alternate between games I currently own, as well as other Pokemon games. For example, I tend to play a fair bit of Mystery Dungeon, as well as Emerald, due to my attempting to raise up a team to get myself Ho-oh, from Colosseum.
I'm also an avid RPG fan, so I tend to play games like Final Fantasy, Kingdom Hearts and the Tales of series of games, when I can and want to. At current, though, I've been training up a few Pokemon on my Diamond, as well as participating in a Challenge set my SilverSmeargleSplatter, on my Pearl.