I've barely touched the Battle Tower/Frontier/Arena/etc., but I have started back up playing Pokemon Colosseum and I must say that though I like the aesthetic and battle system, there's pretty much nowhere to grind/make money.
In other, far more angsty news, my PS3 crashed a few days ago for no discernable reason. A system restore was eventually in order, but all game data was still there. Good, right? Well, there's one thing it didn't remember: All the profiles on the system. Now my brother and I have no PSN accounts and so all the DLC we bought is nonfunctional (and, in the process, we've fallen prey to an infamous glitch and/or misguided security feature that nullifies Trophy acheivement in LittleBigPlanet unless game data is erased). Solutions are being tested for all of the above, and all I hope is that I don't have to buy a bunch crap all over again or never be able to get another Trophy (that, or erase my LBP data).