As I'm at uni and get a lot of time off, I generally dislike weekends.
1. There's more people in the city centre, it's heaving at weekends. Everyone brings their screaming kids to wherever I want to eat with my girlfriend.
2. Again, it's heaving. I get two busses to get to my girlfriends and at weekends it's a pain. Then Sundays don't have as many busses! Add to the fact that there's the yorkshire racecourse that has events some weekends, that makes any kind of travel a disaster. Not just busses for getting to my gfs though, trains getting to and from my house and student house 3 hours away.
3. Nights out. Mates always want to go out friday or saturday nights (I count the weekend starting friday night =P). Because for some reason they prefer going out when everyone else is out so they can not talk to them, not be able to sit anywhere or get to the bar. (We're not really clubbers, more like pub-crawlers so sitting down is quite desirable).
4. Deliveries/Post. You want to order something? Better not be Thursday onwards.. because that thing that's meant to be next day won't get there till monday at the earliest.