TeeFury is the first a-tee-a-day site that I discovered.
The Second one was Shirt Punch, which has three tees every day, two that references pop culture and one that references TV.
Here are som other really good sites:
Threadless , Here are some relly good ones, the designes at voted on by members and get printed when the ranking is enough.
Shirtwoot, Is is another ranking site, with a smaller amount of tees.
TeeTurtle, is a sneaky site, the usally have the most popular 24h tees for a longer time, especially pokemon tees.
Pampling, is a good Spanish site, with ranking (I think, not sure)
TeePublic, random site
Neatoshop, random site
Once Upon a Tee, tees categorized by themes, e.g. pokemon, Harry Potter
RedBubble, Here you could find almost every design printed at the 24H sites, but at a higher price, printed at order.
La Fraise, the strawberry in French, similar to Pampling
Nerdoh, kinda similar to LETN
Some link to my favorite designers