In all seriousness as a working class Welshman from the Valleys, the thought of Rugby Union being a sport for the toffs makes it all the more enthralling.
I remember us playing at some private school in Dorset, barely a game, tread on a fair few hands that game.
Formula 1 (and just about any motor sport on 4 wheels)
Anything to do with horses
Anything to do with boats
Cricket (unless you are actually foreign and apply via some dodgy residency rule. Or Welsh - the 2 are not mutually exclusive)
Anything to do with guns, bow and arrows and other projectiles.
Anything requiring snow and/or ice