Not knowing you or what you enjoy eating - other than the 'c**p' you've mentioned LOL - it can be hard to suggest substitutes but whatever you settle for the key is to have a supply ready and waiting so when you get the munchies in the evening, they're as easily grabbable than a packet of Wotsits.
Firstly don't buy them!
Carrot sticks, small cubes of cheese, one buttered sesame seed Ryvita, 4 or 5 raspberries, one Ryvita Thin any flavour ........
Other thing you can do is to actually vary your activity in the evening - do you have any ironing you could do, have you cleaned inside all the kitchen cupboards recently, could you go for a walk, phone whoever and have a chat? - anything!