As far as scenes being stuck in my head, as a reader, I tend to remember bits of imagery the best. Nick digging bot flies out of Jordan's brain - pretty sure that visual's never leading LOL. Mare's lobster-clawed priest - he stayed with me (haha). Nick walking around inside that dead woman's body in Hawk and Handsaw... Yeah, I tend to remember the gross stuff, apparently! LOL
When I'm writing, it's the really intense scenes that stay with me. The climactic scenes of both Broken and BMS... the first zombie chapter of Undead... the arrhythmia sequence in CC. If it my makes MY heart race while I'm writing it, it'll stick with me for awhile.