I've got a td6, so the sounds probably aren't as good as the ones on your kit. I only use the internal sounds for practising with.
I bought BFD and DFHS. They are WAY better than the internal sounds.
If I had to recommend ONE piece of software then I'd buy DFHS CV
http://www.toontrack.com/custom_vintage.asp. The sounds are great and it integrates with v-drums (especially the hihat) much better than BFD (sorry fxpansion, but you know it's true !)
Try it, you won't be dissapointed.