Bite prevention
Everything here is something I use myself. Be clear what these are, though: in areas where mosquitoes actually carry something I use these sprays, but nothing beats long sleeves and light trousers covering as much skin as possible, especially in the evening when it cools down.
I started using this after reading the Marines swore by it. For three years I played football for a British Army 11-a-side team, and they said they all took it with them when doing training exercises in the Borneo jungle. It's my personal favourite and doesn't feel like chemicals. It doesn't last as long as Jungle Formula, but it lasts long enough, and smells lovely.
What I use if I know I won’t be able to reapply for a while. DEET-based, so it lasts longer than the Avon, but it doesn’t smell anywhere near as nice.
Genuinely good, and the one that buys you an undisturbed night. Check your destination’s sockets and pack an adaptor.
Bite treatment
Because some always get through.
I love this product. Painful for a couple of seconds, then it zaps the bite and that is the end of it. Genuinely life changing for someone whose bites used to blister every time.
What I'd actually buy first
If you buy one thing, buy the bite healer, because it is the only item here that helps after the mosquito has already won. If you buy two, add the repellent. If you're going somewhere rural or tropical, add the plug-in and the net and stop pretending you'll get away with less.
And a genuinely useful non-purchase: long sleeves and loose, light clothing at dusk. Free, and more effective than most people expect.
Straight about this list: everything here is something I use myself, which is why it is short. It is not a survey of the market and there are plenty of good products on it I have never touched. Repellents come with their own instructions, which matter more than my opinion: read the label, mind the age limits, and ask a pharmacist if you are pregnant, treating young children, or taking other medication. Nothing here is medical advice, and none of it protects against mosquito-borne disease, which is a conversation for a travel clinic before you go.