I've been referencing Allen & Greenough's New Latin Grammar
from the College Classical Series (http://caratzas.com/index.cfm?category=19
). So far, I don't have any real complaints. I opted for this one over the apparently more "user-friendly" Bennett grammar mostly for aesthetic reasons. Bennett uses Js instead of Is in some of his tables/example sentences. For some reason, this really bothers me. Also, I think the Bennett grammar is advertised as being concise--this didn't appeal to me, and I don't think it will appeal to you.
Gildersleeve also has a good one from what I hear, but I don't have any personal experience with it.
a link to Bennett: http://www.amazon.com/New-Latin-Grammar ... 767&sr=8-1
a link to Gildersleeve:
http://www.amazon.com/Gildersleeves-Lat ... 818&sr=1-1
Another factor that played into my decision is that Allen & Greenough's grammar was available at my school's bookstore. It was simply convenient.
I'm sure you could find Allen & Greenough on amazon.com