I've been doing some thinking about the 23rd pick and I've came to a conclusion, there will be some good to great players left on the board at 23. Going back a few years, I'll list off some names that were taken after number 23 (stopping at the end of the third). I'm not saying all of these guys were good enough to be the 23rd pick, but I do think any one of them is a starting caliber player and wouldn't have been so bad if they were taken at 23. If I were to go into the deeper rounds, I could still find a lot of starting caliber players that would have been a decent grab at 23.
First though, I want to point out that on offense and defense, there are 13 different positions on the field. Which means that at 23, a guy should be no worse than the third best player at his respective position. Ideally, he'd be the best or second best. The reason I say this is because it's very rare that there are more than 2 or 3 guys at each position that are truly first round good, taking a player after there's been a run at that position is a surefire way to overdraft somebody *cough* Gosder *cough*.
Also, this isn't an all inclusive list, I'm sure there are good players in those drafts whose names I just don't recognize.