Sorry, I was kind of assuming you weren't already locked into Rogers. If you are, I don't know what your options are but the closest thing we have to the iPhone for what you're looking for (just casual kicking it around kind of stuff, nothing business related or anything like that) is the HTC touch diamond. All I really know about it is that it's basically the main contender for the iPhone, with slightly more features, but I think the navigation isn't as good or something. No idea.
Beyond that, there really isn't much competition if you're set on a good media player interface, don't care about it being a completely closed system, and are just using it for entertainment purposes. For work and straight up communicating, the Curve is what you'd probably want to be looking for, with the PEARL being an option if you want something smaller.
If you just want internet access, I'd say go for a PEARL and an Ipod Touch. They kind of play off each other, since I don't think the PEARL has wifi, but the data plan will be a lot cheaper and the thing is practically free. I should point out that I'm a bit biased here though because I hate the idea of sharing a battery between my phone and multimedia player.