What sort of zoom range do you want?
How compact do you want it to be for a travel lens?
What is your budget?
I’ve got the 18-135mm Nikon lens that was sold as the kit lens with the D80. It’s a decent lens, while not being outstanding. It’s a good buy for the money.
If I was buying now, I’d probably go for the 18-105 VR lens as my ‘normal lens’. I have VR on my 70-300 & it really helps in low light. I sometimes miss not having it on the 18-135.
You could also consider a used Nikon 18-200mm VR. I borrowed one from an old colleague once & it’s a great lens – decent performance throughout the zoom range, but it’s heavy & quite a large lens for something to travel with.