In my experience, the real key to French toast is the bread. Just basic good quality eggs well blended with a little milk is all you need, plus some cinnamon and butter. No fancy recipe. But that bread? It'll make or break your French toast. You want good thickness, like 1/2" to 2/3". I haven't had good success with multi-grain... white always seems to be the best for making French toast.
Next most important thing is cooking it. Nice flat pan is usually best, and I prefer to use a little butter for resistance to sticking. Hands down, a good quality ceramic coated pan will help give you excellent results. Teflon is OK. You can of course go the old cast iron route, but it's a little tricky to work with.