I've heard some positive things about having them embroidered professionally or otherwise printed by a national outfitter. Fog Creek has had good responses [1] doing this, and it's something that we're considering at Darkened Sky. The downside is that we would need to maintain our own inventory, which would get costly, as well as potentially wasted if we move to a new design, but have a lot of of the old shirts already printed.

SpreadShirt actually looks decent, but I'd love to see a blog order a shirt from each of these services, and then write up their experiences.

[1] http://www.joelonsoftware.com/articles/customerservice.html

CafePress uses thermal printing (bad) and they'll give you 20%. Zazzle is better quality, also 20% of the sale. GoodStorm (recently acquired by Zazzle) will give you 70% iirc. SpreadShirt is another option.

I'm working on the sweet spot between Zazzle & the Reddit approach - American Apparel with better %s than CafePress/Zazzle, focused entirely on startups, outsourced - drop me an email - roddy at StartupSchwag dot com