Favorite format is SACD, because it generally sounds better to my ears, but DVD-A is a very close second. Both SACD and DVD-A are completely dependent on the mixing/mastering though, because I own some titles that sound hardly any better than the CD version, and some that are like night and day.
Most of my money is spent is on redbook CDs though...because most of the titles I want are not on SACD or DVD-A.