Rihanna and Chris Brown
Rihanna and Chris Brown dated for two decent chunks of time, the first of which ending after he beat her senseless. Never a good sign. Nor was taking him back after that, but she's moved on with Drake ... thank goodness. Good luck, Karrueche!
Amy Winehouse and Blake Fielder-Civil
Perhaps the most lethal of any love we've ever seen, Amy Winehouse and Blake Fielder-Civil abused drugs so fervently that she could never recover from that viscious cycle, passing away at age 27. He, meanwhile, ended up locked up for a long time.
Mel Gibson and Oksana Grigorieva
Mel Gibson and Oksana Grigorieva weren't together long, and for good reason. These two went nuclear on each other ... well mostly him on her voicemail.
Jessica Simpson and John Mayer
Jessica Simpson and John Mayer equals sexual napalm. That's never healthy. Only sexual.
Ronnie and Sammi from Jersey Shore. These two need no introduction. Just clips of them brawling. Of which there are plenty.
Justin Bieber and Selena Gomez
Justin Bieber and Selena Gomez had a long love affair that involved him taking her virginity and a whole lot of partying and frequent breakups, fights and general emotional turmoil. It's possible it wasn't meant to be. And by possible we mean obvious.
Amber Portwood and Gary Shirley of Teen Mom fame were fighting more often than not. Often, things even got physical between the on-off couple, and it was scary.
Lauren Conrad and Jason Wahler
Lauren Conrad and Jason Wahler break up on The Hills. It was a frequent sight. Very frequent.
The Bachelor couples rarely stand the test of time, but Jake Pavelka and Vienna Girardi were doomed from the start. Reliver their amazing public breakup and you will see why.
Jenelle Evans and Courtland Rogers
Jenelle Evans and Courtland Rogers, who are still technically married, were only together as a couple for a few months ... during which she aborted his baby and both were arrested for heroin possession and assault. They also feuded on Twitter a lot - even by her standards. Not healthy.
Britney Spears and Kevin Federline
Britney Spears and Kevin Federline were married two years and had sex at least that many times, as evidenced by their two sons. How in the world did these two ever get married? Okay, we can grasp why K-Fed married her (see photo). Just not the reverse ...
Taylor Swift and Joe Jonas
Taylor Swift has had a lot of boyfriends and a lot of breakups. Joe Jonas is the only one to dispatch her via voicemail, however.
Farrah Abraham and James Deen
Okay, it was a fake relationship that she tried to pretend led to a leaked sex tape that was actually just a porno. But still, Farrah Abraham and James Deen simply DID NOT WORK as a couple.
Bristol Palin and Levi Johnston
There are no words.