I don't appreciate it when the hotel doorman wants to take my small rollaboard out of the trunk and then roll it to the front desk for me. If traveling with the family and a ton of stuff I have no problem tipping bell services.

I take the rental car shuttle frequently in Houston and the shuttle bus is not passenger friendly. The step up is tall and the driver never seems to be around to assist with the bags. I would say only about 25% of the time do they assist and I tip accordingly.