The one thing that kills it for me with Rihanna, other than I think she is overrated, is her new tattoo. Tattoo's aren't necessarily a deal breaker for me as long as they are tasteful, some chicks can even wear a pretty mean arm sleeve, but tattooing your forearm up to the back of your hand and knuckles is an immediate disqualification.
It even shadows her finger nails. YUCK!