I prefer an ale or a bitter. Lager is... well, it isn't exactly a great taste. The reason why lagers are served ice cold is because it overwhelms most of the taste and just leaves you with 'cold and refreshing'. Hence, ales are served at room temperature, to preserve the flavour. Fortunately, I live in a brewing town, so there's no shortage of choice around here. My regular does a fine pint of Hobgoblin, which always goes down well of an afternoon.
Although to be honest, I'm quite partial to a decent single malt.