I’ve had DC Access for about six months and am really pleased so far. The installation guy was quick and tidy and customer service (the little I’ve needed it) has been great. And their office is in SE—yay local! The 1.5Mbps/512kbps speed ($35 per month) seems to be working just fine for streaming movies and music and basic internet stuff. Occasionally I’ve had slow moments with movies, but I do live in a basement and haven’t updated my computer since 2007, so that might have more to do with the problem than the internet provider.
So yeah, if all you need is internet and you live in Capitol Hill/H Street or Adams Morgan, my vote goes to DC Access.