I've always found the ones that give a Wikipedia summary useful

Water is a really good shout, but instead of buying a bottle at the airport (which can annoyingly expensive) you can bring an empty refillable bottle and fill it up after security!

It's good for your wallet and the environment

The Alps - driving up those alpine hairpins as a car nut fuses the amazing views with amazing roads, absolutely breathtaking

There's no metric that's similar to Karma here I don't think, so there's probably very little to gain by reposting popular posts