MeUndies is an excellent example of niche selling of quality goods on the net, and making it fun. They sell really comfortable underwear in several styles in a variety of bright colors for men and women, along with sock and t-shirts and their just-announced hoodies and sweatpants.
They have all manner of plans, like buying in packs or auto ship once a month for 20% off. Here’s a tip: Get on their mailing list and wait for the big sales, like 30% off. You won’t have to wait long, they’re always doing something to get you to buy. They also sell bundles and subscriptions (one a month.)