I do English Lit, I'm in my second year and honestly for me I think it depends on your teacher, my first year was AMAZING, I totally loved it, but now I have a new teacher and I'm not too sure.
About the course itself, it's quite interesting and it's taught me so much about other cultures and issues, such as feminism and conflict in the East. It's extremely useful for writing in other subjects, I can work to deadlines more efficiently, and I now know how to correctly lay out a critical essay and footnote properly.
I've found it easier to pick up marks in coursework and the exam that my other subjects and theres much more variety due to the wide range of reading you have to do, last year I studied Pride and Prejudice, The Duchess of Malfi, Othello, The Yellow Wallpaper and lots of unseen poems, this year I've been looking at The Go Between, A Doll's House, 100 Anti-war poems, The Kite Runner and again unseen poems on a number of topics.
As for fourth subjects, I'd suggest business as that can be really fun and would link in with psychology and law, but also has elements which English would help with. With Law at A Level/Uni, I've actually heard that they prefer if you don't do it/They don't particularly care if you do as you're learning new things anyway.
Good luck(: