Travel lens advice for my new D90

Hi All,
Hope this is the right forum to post in...just joined.

I'm looking for advice on a versatile travel lens to acquire and bring to Europe (and maybe other equipment/gear if you think it's relevant). I've heard a lot about the 18-200mm VR, but then I hear about the 16-85 VR and the Tamron 17-50mm and I get a little lost in the decison process...

I have a D90, and 2 lenses: 18-55mm and 70-300mm. Relatively new to the hobby ( 9 years, if that matters), and on my 3rd DSLR. Always just used a kit lense before, but I've learned enough to step up now, methinks

I'm travelling to Europe soon, and I'd like to take lots of the usual shots: monuments, family shots seeing the 'sights', indoor art-gallery-type shots, and lots of landscape (wide angle?). Most will be outdoor, I think...

Hoping to spend under $600 CDN, but willing to buy the right lense if necessary (I guess, up to $1000 CDN).

Thanks in advance,
Lance