So to (hopefully) bring it all together, what's you're vote?
Personally, I used to have a soundcard about 10 years ago. When I built a new system, I missed it out and just used on board which worked fine for my needs. My latest system doesn't have a dedicated sound card either.
Here's where I am:
My HTPC uses the on board sound but I might be in the market for a sound card. However I don't think the £50+ will be worth it for the difference it will make and it seems spending less than that is a waste anyway. So I'm not considering buying one really and think they are only good for serious audiophiles or home theatre people (which is out of my league too!).