I have pretty much stayed entirely with MS Visio Architect for Visual Studio as well since it comes with my MSDN subscription, and that most of the companies that I have been with have it as some sort of defacto standard...I have also strayed off and used ERwin from CA but as a smaller shop I just can't afford (or justify) $4000 USD for a data modeling tool; especially since I tend to build my database from my objects and not the other way around.
Lance
P.S. I just noticed that CA is offering a great deal right now on ERwin! You get a $200 iPod Nano with every purchase! LOL! What a steal!