I get Raids quite often but typically only those associated with the latest boss killed or I'm "being hunted" quite often. I rarely see Fulings or Drakes, and the Ooze Raid is...kinda sad as it is easily the easiest to contend with compared to the Skeletons and Draugr with their potential bow attacks and ability to swarm in melee. And the Imp Raids....are just plain annoying, they attack everything in the vicinity and I end up finding damage they caused many days after they caused it. I can't remember the last time I was attacked by a Graydwarf or Troll Raid compared to any of the others though.