Which lenses for travel kit?

[Tijn]

My ideal travel kit on that level would be...

Canon EOS 60D
Canon EF-S 15-85mm f/3.5-5.6 IS USM (not L build quality but very sharp, not a fast aperture but a perfect wide zoom range for a crop camera; light-weight also)
Canon EF 70-300mm f/4-5.6L IS USM (versatile supersharp L telezoom for anything 'tele').

These both fold up pretty neatly for their range (size-wise). With these two lenses you'd have the most versatility and great image quality, in a very portable package. For anything "extra" you could take a prime of choice for some low-light shooting at your favorite focal length.

[Caps18]

My small travel kit (Pelican 1450 case)

5DII
EF 16-35mm f/2.8L II
EF 300mm f/4L IS
TS-E 17mm f/4L II
EF 85mm f/1.8

Extra battery & CF card

[Marsu42]

My ideal travel kit on that level would be...
Canon EOS 60D
Canon EF-S 15-85mm f/3.5-5.6 IS USM (not L build quality but very sharp, not a fast aperture but a perfect wide zoom range for a crop camera; light-weight also)
Canon EF 70-300mm f/4-5.6L IS USM (versatile supersharp L telezoom for anything 'tele').

* For zooms covering every mm: +1 for that. It is interesting - before I purchase anything, I read tons of reviews, and I always end up with exactly the gear I had the best feeling with when touching it in an electro market for the first time... like the 60D (vs Nikon D7000), 15-85 (vs. 17-55), 70-300L (vs 70-200L) ... I think for travel in contrast to a pro application, the most important thing is that everything "just fits" and "just works".

* However, I really think the description "travel" many people give is a bit thin. Are you doing a safari or bus tour with "photo stops" and have 1 minute to shoot every rock around you? Then a couple of zooms are for you. If not, I personally would go with some lighter, but high iq primes and walk around a bit to frame the picture. As Ken Rockwell said: Primes take better pictures because you don't just "zoom an shoot" but have to walk and think. And cropping is no problem, after all it's digitial.

[stevevihon]

The first two cities you mentioned both have strong architecture and great museums.  DC has a lot of monuments and Chicago has a lot of great buildings, Millennium Park and the lakefront.  A wide angle zoom, a fast prime and a tripod would be a good starting point.

I live in Chicago and would recommend the following as possible things/places to shoot:
1.  Millennium Park, especially a sculpture named Cloud Gate which we locals refer to as the Bean
2.  If you want a nice shot of the skyline from the lakefront, right by the Adler Planetarium is a great view of the lakefront / city
3.  Willis Tower (formerly the Sears Tower) has sky decks that jet out a few feet on the 103rd floor -- great views of the city
4.  If it is closer to spring, consider the architectural tour on the Chicago River
5.  If you have any interest in shooting photos of Jellyfish, the Shedd Aquarium has a nice (but small) exhibit through May of jellyfish in tanks against very colorful backdrops