Hey - anything really that isn't syrup/sugar based. At the end of the day your health is the most important thing. From what I can gather form other threads, the best things are:
Headache - paracetamol
Sore throat - paracetamol/ibuprofen
Cold/run down - paracetamol and hot St Clements drink with dissolvable aspirin.
Poorly tummy - rennies (just the plain chalky ones).
Obviously I am not a pharmacist etc, but these are what people have recommended over on the LL forum over the last few months.
A xx