Jimmy and Cindy works for me because it's not like they both seemed to love each other the whole time. It's sorta like there were little hints that got more and more intense as the series went on.
That said it really seems like Jimmy's antidote to his love potion was just shitty.
Sheen fell in love with Libby.
Jimmy fell in love with Cindy
Carl still talks about how hot Jimmy's mom is.