My top 5 would have to be:
1. An ID : Always helps to have one handy, wouldn't you agree
2. My cellphone : My cellphone is great to stay connected with my loved ones back home, work and also acts as my torch, my navigator and my notebook.
3. A Camera and the Go Pro: You got to take photographs to freeze memories right?
4. A bag: I need a carry along that helps me keep all of these safe.
5. Traveling cash : No money, no happy travelling. You do need money to move around freely