I'd go for straight lit becuase, as others have said, it tends to be the most respected by universities and in my opinion, it's also more interesting. Obviously it will depend on your personal preferences. If you like reading and analysing texts, go for straight lit. If you like analysing speech patterns, dialects etc, go for straight lang. If you enjoy both, go for lang/lit combined. Another thing I'd say is that straight lit is very similar to GCSE, just harder and more in-depth, whereas straight lang is nothing like GCSE; so if you enjoy GCSE English lit, it's very likely that you'll enjoy AS, but this may not be the case for lang. If you're thinking of doing English at uni, you'd be better off doing straight lit as otherwise you might limit your options.