I use a few. Either Stowy McStowstow (and if I'm able to, or feeling like it, I'll add in "Archduke of Stowland, Heir to the McBaffbaff Dynasty, Master of the Bo Staff" at the end), CrazyMcNinja, or McNinja.
In WoW, I generally stick to two: Malkanis (I saw Mal'ganis as a name in WC3 editor, and so I switched it up), or Silithus (after the zone Sithilus in WoW). Other than that, I try to be creative, but I usually end up looking for named, then messing with them. My brother on the other hand, named his Mass Effect 2 character "Thundah" so his name is Thundah Shepard.