I find handguns the most entertaining and satisfying to shoot. They are also highly suitable for indoor ranges. In another life,I was able to impress my friends by picking roaches off the wall with their airsoft pistols.
Rifles are difficult for me to shoot past a couple hundred yards. Plinking offhand close by isn't the same as firing a high powered centerfire off a bench at long range. I'm probably doing everything wrong. However, I almost never get to shoot anyways, and I probably can't find enough rimfire to take a class. And I don't really have a suitable rifle anyways.
I might be a shotgun guy if I could do it affordably. I can't.
Machine guns are a sad joke. I might be able to afford a to run a few magazines through a rental if I save up, but that's it. Seriously, the absolute cheapest transferable costs as much as a rather nice used car. That's bucks. And then anything interesting is likely several tens of thousands of dollars. And that's today's prices. Short of winning a Powerball, I'll likely never own one. I'll be lucky enough to fire one.