I own S&F and DotF, and have read T&B and S&S
T&B: The best of the lot, lots of crunchy bits, and cool prestige classes. This one reaches out, grabs hold of your throat, and says "Play me!"
S&F: New feats, new weapons, lots of prestige classes. This one also has good prestige classes, but was marred by horrible editing. I found it flawed but decent.
DotF: While the section on temples was interesting, the feats, items, and prestige classes didn't seem that interesting. When was the last time you sat down and said "I'll play a Templar tonight."
S&S: This one just seemed really boring. While the feats were okay and the section on instraments pretty good, the prestige classes were very generic. I think that prestige classes aimed at the rogue can have trouble because of the customizability of the rogue.