Yea I agree. St. Andrews looks really nice being ancient and pretty and all but then give some credits to warwick which is only 40 years old. Looking at the pics I wouldn't say it's ugly. There are a lot worse ones.
Anyway, I would go for Warwick given the choice. When the admission person came over, she said that Warwick was rated higher in teaching quality than LSE or something (no offence to LSE people, LSE is still top for econs of course). Look at the rankings as well.. Warwick 4th (above oxford this year) and St. Andrews 13th. Warwick is also known for it's links to industry and employers.
So it's basically another question between pretty uni and good rep uni. Up to you, St. Andrews is still pretty good. I mean Prince William went there didn't he?