My MB : Mobil 1, as specified in the manual (0-30 i guess), every 8-10k miles (when the display reads 1500 miles for next oil change). There's a lot of comparable quality material in the thread, and I feel bad I change it less often than the rest!.
SUV and hobby : Quaker State 10w-40 + 1 can stp every 3500 miles, but these are not-so-technically-advanced engines (heck! an all steel 1967 454 V8 with twin 4barrel carbs with screw adjustments and no computer!, it can be fixed with duck tape, a screwdriver, a 1/2 in hex key and the pump will not move the oil!)