Here's a list I posted a while ago
1. Tuna, sweetcorn and chives/spring onions mixed with fromage frais/extra light mayo
2. Bolognese
3. Cheese and beans
4. 5 bean chilli
5. Tomato, onion, smoked paprika and bacon, all reduced down
6. Cottage cheese mixed with some chopped prawns
7. Prawn marie rose made with fromage frais, ketchup, lemon juice and some cayenne/smoked paprika
8. Tuna mixed with extra light laughing cow triangles and some chives/spring onions, then grilled. Mmmm - cheesy tuna!
9. Any sort of stew heated up on a potato
10. Salsa (preferably chilled)
11. Plain yoghurt, coriander, and diced cucumber and/or red onion
12. Sauteed mushrooms
13. Scrambled egg, tomato and green pepper
14. Curry
15. Coleslaw
16. Tuna, red onion and pepper
17. Philly, chives and chopped ham
18. Philly, chopped cucumber and tomato
19. Tuna, onion, apple and celery in mayonnaise
20. Chicken and sweetcorn
21. Roasted vegetables
22. Cream cheese and spinach
23. Tomato, turkey and broccoli
24. Smoked ham and pineapple
25. Bacon and mushrooms
26. Bacon and baked beans
27. Bacon, onion and sweetcorn
28. Cheese and marmite/bovril
29. Crab meat and coleslaw
30. Chickpea dahl
31. Hummus, grated carrot and coriander
32. Smoked haddock/mackeral and sweetcorn
33. Egg mayonnaise
As you can see there's tons of things you can put on a baked potato!