I fell for Dead or Alive Xtreme 2. Cheap as hell when I got it and I haven't gotten a single Achievable in it for obvious reasons. Spent enough time on it to nearly complete Tina's swimsuit collection...SO MANY JET-SKI RACES...I think I filled up an Xbox 360 memory card with DOAX2 screenshots that I'll never bother with again. It's that one ridiculous game on my Gamercard.
I bought Soul Calibur IV because my friend told me to. The sex appeal came far later.
Aside from these, sex appeal has never really been a driving force behind the games I buy. That's mostly "What guns are in it?" and "How much customization do I get?" Damn you, Brink...