A passport works, but it a) doesn't list a home address, which is sometimes necessary and b) is too bulky to conveniently carry around.

When you renew your passport, you can also get a passport card for an extra $30 or something. They're only good for land/sea crossings (no flights) from US to Canada, Mexico, but you can put it in your wallet.

The downside is again that it's non-standard form of ID, but it is a photo ID and may be useful

Depends on the size of you pockets