If you are looking for something unique go to Past Era on Westheimer between Shepherd/Kirby in the Antique Pavilion. Everyone that works there is nice and very helpful. It was the place out of everywhere I went that I felt most comfortable giving my money too. Also, they have a lot of rings they dont keep out front becuase they are trying not to draw attention. Worth a look if you dont want to buy the same ring someone else has.
http://www.pastera.com/ Diamond Cutters is great if you are looking for something custom (in the sense that the setting is not branded), they do all their own cutting (hence the name). It is expensive but very high quality.
[This message has been edited by aggiemike02 (edited 4/6/2006 9:35a).]