Another vote for Great Beginnings. I bought my older DD's twin bed from Target because I just assumed Great Beginnings would be too expensive. When it came time to purchase younger DD's bed, I was surprised at how much Target was charging for a full bed! I went to Great Beginnings and was pleasantly surprised at their pirces.
Procrastinated a little while, then went back to GB to finally buy a bed. The bed I was considering was now discounted because a new model came in and they gave me an additional $50 off because there was a crack in the one leg (the bed is completely fine and you can't even see the crack).
Long story short - the full bed I bought from Great Beginnings was cheaper than the twin bed I bought from Target - and nicer!
I'm a big fan of GB and especially their clearance items!