In the recent years when we've been competing for the top 4, and especially in 2002 when we finished above United, I always wanted Everton to beat Man Utd. I can't stand either club but if there is a certain result that benefitted us, I'd want it.
Last season as we were competiting more with the blue shite, I wanted United to beat them. Simple
And if they were playing each other and it had nothing to do with us, I'd want them both to lose with several red cards, broken bones and inquiries by the FA!