Agree with other ids. Depending on how much space you have, in order of usefulness I'd keep:

a) blackthorn for sloe gin (though you can usually gather enough from hedgerows so it's a luxury really) It also flowers early, before the leaves, which cheers one up in spring. But if you're limited for space, remove it in due course and replace with something else.

b) hawthorn - like the sloe, it's in the rose family, which are usually non-toxic. I'd be keeping it for the birds, which keep down pests and improve the health and crop bearing of your other plants. But again, if you're pushed for space, replace it by another fruit tree.

c) I'd keep the woody nightshade - the berries are so beautiful as they turn from green to yellow to red, with a sort of translucent glow. But totally non-useful for you, and toxic. (Once when I was ill as a young child and awaiting a doctor's visit, my mother warned me to remove the vase of woody nightshade from beside me bed, in case he got the wrong idea ;-) )

d) the sycamore will be nothing but trouble - get rid asap.