From Hammer...the Hawg. Maybe the Hawg Zilla. Or, if you can find one, a Real Deal. From other manufactures....Robo Rule from Track is a good one. The Epic Battle from Roto Grip is another one. The Passion from Storm is a possibility. For really, really heavy oil, Visionary's AMD Centaur Particle works wonders, but only if you have loads of oil out there. Best value for the money is probably Visionary's Granite Gargoyle, that could work. If you like hammer, get a Hawg.
Chuck