The lagers that I always find go down well are Kingfisher, Castlemaine XXXX and Tennent's. Mmm
By the way, the best place to go for lager is definitely Prague, especially for the Staropramen - lovely taste, goes down really easy, doesn't give you much of a hangover and is about 70p a pint on average.
You can get Staropramen over here in Britain but it tastes totally different and is a lot more fizzy. Need to get back to Prague quick, methinks!