When it comes to Yusuke, I'm pairing stupid. But I'll give you all the ones I know of.

Yusuke x Hiei
This pairing could never happen. For one thing, both of these people are straight, although it's nice to imagine them, well, not straight. x] Yusuke and Hiei's personalities are totally opposite. It could never happen. Unless you drew it. Then it could happen.

Yusuke x Kurama
Um...okay...Again, totally different personalities, but Kurama can handle a lot of things, and I've seen him handle Yusuke a lot. I've taken personality tests, and which spirit detective would I go with tests, and for personality, Yusuke, for compatibility, Kurama soo...though those quizzes are a bunch of bull, I guess we could go by those. x]
Who else does that? XD!!
Yusuke x Kuwabara NO.
Yusuke x Koenma
Explain to me how many times these two even interact. A few times, but not enough for them to run up and start making out. So no, it probably wouldn't happen.
Yusuke x Younger Tugoro NO! I've read this before though. D:< Eeew.
Yusuke x Keiko
Very much true. There's proof. They marry. HA HA!
Yusuke x You/Your Character
In your dreams, babe.

Have you seen a pairing not on here? Let me know!