I went to an audiophile forum to ask what the best set under $100 was and the Sennheiser 280's for $85 were the most recommended and a set of Koss head phones (can' remember model) where also highly recomended.
They spoke highly of the detailed sound, like sounds I don't hear on my AIWA receiver because I have crappy speakers. The receiver isn't great either, but would be fine with a set of headphones or expensive speakers for my uses.
Anyway, if you can swing the extra $15 the Sennheisers I'd do that, but if you get another brand (besides Koss) I'd just get the cheapy $30 pair because there probably isn't a big difference between those and their more expensive offerings.