Near Rhymes:
* Vanessa (this is the closest you'll get to a true rhyme)
* Janessa
* Chanesha
Eye Rhymes:
* Tanisha (sounds similar, but doesn't rhyme perfectly)
Ultimately, the best option depends on what you're looking for in a name. If you want a true rhyme, you'll have to look for something that is slightly different but still sounds similar.