AT 45 degrees I feel all the stress in my delts. Many standard incline benches (non adjustable are at 45, and I think thats very bad). To me the ideal is 10 - 35, but you should do whatever is more comfortable to YOU.
I do 30, 45 & flat in my DC training. I feel the most comfortable with 30, the 45 works my shoulders pretty hard. It depends on what exactly you are wanting to target.
Hmmm, so what would you guys recommend if the only incline benches in my gym are fixed at 45? I'm doing 5x5 so I don't really want to use dumbbells (can only go up by 10 total and not 5). There's no power rack I can use to rack the bar and put an adjustable bench under it...