Best chain lubricant for commuter/utility bikes?
Tri-Flow works the best.  Any wax or lubricant that contains wax is only somewhat useful on a brand new chain, or a chain that has been thoroughly cleaned.  Wax lubricant does not work well when riding in wet conditions because a lot more road grime gets kicked up into the drive train and the wax tends to do the opposite of what is advertised.

You aren't going to find a chain that doesn't leave stains on your clothes.  Your best bet is to get a chain protector to keep your clothes and your chain separated.