Collect all Gold Symbols/Color Prints in both Emerald and Platinum Battle Frontiers. The best I've gotten on Emerald was four Gold, and the best on Platinum three Color.
I like the battles, it's just so dispiriting to get a haxxy loss and have to start again from the very bottom. After experiencing that sequence of events, say, five times or so, I have to put the game down and raise my spirits with something more in my control.
It'd be awfully handy if they put a checkpoint, of sorts, in the Frontier facilities, so you didn't have to always fight fourteen battles against Pichus and Pidgeys after losing in high rounds. I don't know; just some way to make the facilities less frusttrating. I don't buy into the "frustration is necessary to make it challenging" mantra they seem to have.
True, you always seem to run into that one team that was meant to counter you specifically. E.G. battle frontier. It would be nice if there was no double team or OHKO, but oh well...
I suppose I have the same goal of beating the battle frontier in Emerald and in one of my gen IV games.
Also collecting all 493 in Heartgold. I tell you its pretty debilitating after a while, but I figure i'm up to 300 pokes, so why quit now? Same goes for BW as well.
Learn how to RNG abuse, Looks complicated, but I think I can do it. Just wish they had the software for macs though.
Get into the competitive battling scene. After reading all the smogon articles as well as battles and what not, I think I'm going to jump into the gen V scene.