One of the first things I do when I'm on a new project is design a database model. To visualize the model I use a 7 year old version of Smartdraw. Maybe it's time for something new. What is the ultimate program to make a drawing of a database model. Smartdraw is for Windows only. Is there something that can be used on unix as well?
For linux I use umbrello
If you're looking for a cheap solution/tool without any reverse/forward engineering capabilities, MS Visio might be your best bet. However, if you're planning to invest some money toward ERD tool, spend it on ER/Studio.
I used to use and be champion of ERWIN. As soon as I started to use ER/Studio, I became fan of it. I'm an enterprise data architect at one of the Fortune 100 company and I don't know how to get my work done without it.
PS: I don't have no affiliations with any of those products and companies.