Some are less interesting than others. There are a number of low level fixers I'll avoid though - you know the type, every time they get into an atp event, they're instantly off to sell correctscore, handicap, under, etc etc.
Some career ambition that ..... fight to get your ranking up, so you can get paid lots to lose heavily.
There are really no players whose matches I refuse to watch, all depends on the matchup. I watch any match with an interesting matchup (assuming I have time). On the other hand, I usually don't watch even my favourites matches against walking byes. But if I happen to see a match against a walking bye, I like Sharapova's matches the least, I can't stand that shrieking. Vika is just as bad a shrieker, but I just happen to like her more. But on men's side, I obviously can watch any player's match.
2014 Australian Open Champion | 2014 Monte Carlo Masters Champion | 2015 French Open Champion
2008 Paris Masters Champion | 2014 Toronto Masters Champion