Well, I only have two so these are my current favorites:
PAM 036 - The tobacco dial and Titanium go well together
PAM 089 GMT - The Titanium and Anthracite Dial work well together
One in my collection that uses a Ti mid case and polished bezel is the 172 (long since out of production and supposed to be Tantalium not Titanium)
I also like the 082 with its Blue dial and hope that we someday see a rep of the new 331 (Ti 1950 case GMT).