I usually tip $5, but I do it because I often push checkouts past the deadline (even for late checkouts). Most of my stays are at the Marriott Suites in Herndon, and I throw out a lot of newspapers and occasionally other packing materials.

I also tip higher at Marriott restaurants than at other restaurants, and I usually get the benefit of the doubt if I show up late for breakfast. However, I will complain if service falls short with regards to housekeeping or at restaurants in general.