What would be the best (easiest to use, cost per photo, best quality) photo printer?

You might consider an Epson Picturemate. The ink and paper come together in packs of 100 sheets for about $30, but the ink will actually last much longer, at least another 30 or 35 sheets, so buy an extra pack of paper. You plug your memory card directly into the printer and away you go! Or you can also hook it to your computer.

The drawback is it only makes 4x6" prints. The cost per print is stated to be 29 cents. And the quality is very good.

It depends on your needs. If don't need prints very often, do like uzurhead said and take it to a photo place. Even if you print a lot, you might be able to get a discount ;-). If you're buying a printer try it out first in store, and compare prints with your own eyes. You'll get better service in this regard at a specialty photostore.

its the ink and the paper that costs on a photo printer. Ink alone can cost around $1.80 on a 4x6 print. Had a photo printer...cant afford to use it. Cheaper to get it done at Staples AND they can help you if you get stuck!