>>42175683This big buddy's STABs hits the whole game for neutral damage or better, barring weird circumstances like Wonder Guard or Steel types with Levitate/Air Balloon. I think Ground/Ice is the best type combination.
Fighting/Ghost is definitely up there too. So is Ground/Fairy (which hasn't been used yet) and Ice/Electric.
The problem with Steel/Bug is a lot of stuff will resist your STABs, often both of them at once. You get walled easily and might have to set up if you want to actually kill anything. I don't think it's even the best defensive typing, that goes to either Electric/Steel or Water/Ground in my opinion. I could see a good case for Steel/Fairy or Steel/Flying too.
Bug is just such a shitty type.