My Wireless Router is eViL!!

I frequent the music remix site linked here as OverClocked Remix a lot, listening to the great remixes of various video games talented musicians post on there.

I also visit a lot of places that involve Flash animation like the Ninjai movie site and Bonus Stage.

However, I made a rather strange discovery. It would appear that if I plug in the D-Link Wireless Router we have (model DI-514, for those that care), I can't access those places unless I have the patience of a Zen Monk. Things load so slowly, it's not even funny!

Yet I still need to plug this in so that my sister can use her laptop whenever she's back in town. I think we need a better router. Suggestions?