Steve, good thread. It should get a lot of responses.
I use whole milk, part-skim or fresh mozzarella, depending on the need at the time. I often mix cheeses. Fresh mozzarella and buffalo mozzarella are lovely but can be a little wet. Whole milk is next, and part-skim does the job if one must watch fat and calories.
Fresh mozzarella is often just sliced into rounds and added to pizza. For the block mozzarella, I usually dice it into 1/2-inch cubes and scatter it over the pizza. It melts into small puddles. IMO, shredded cheese can get a little tough in a really hot oven, especially the part-skim type.
Pizza Marinara is good too. It has no cheese, just marinara sauce, and you can add vegetables, olives, etc. as desired. Grilled eggplant and peppers is a favorite of ours. Mushrooms too.
I like almost any kind of pizza, classic, white, or gourmet. Jack is more of a traditionalist and prefers red sauce on his.
If you want to get some ideas for interesting vegetarian pizza combos, there is The Cheeseboard Collective in Berkeley that publishes its Pizza of the Day on a weekly basis. Reinhart writes about them in his Pizza book:
http://cheeseboardcollective.coop/Pizza%20Collective/z.htm
Rita