KEF has some real nice in ceiling speakers. They just this year released a dipole/stereo model that is great for surrounds but not overly necessary if you step up to one of their Uni-q models. If your budget allows larger the Totem in ceiling are rediculous. Heard them at a trade show with only one playing, not even in a ceiling, with a small sub playing and it was hard to tell the difference between them and the pair of Hawk when they switched between them.
Those are two of my favs. There are so many out there that I have used in theaters and such that it is hard to list them all...so I won't.
Matt