Session IPA is a 'sessionable' style of India Pale Ale. There's plenty of hops in it but generally it's under 5%. The idea is that you have a fair couple in a session.
Mild is one of my favourite type of beers. It's considered 'old man' by most but it's malty, roasted and coffeeish as well as being dark. It's not common to find it in pubs these days. Comes in at around the 4% mark.
Porter is another English type of beer that's dark and roasted. I like it. I enjoy some local porters when I can get hold of them.