Crawlers are a lot of fun, axial for that.
Rock racers are fun to break, axial for that as well.
Shortcourse is a hell of a lot of fun and pretty durable, losi, associated, traxxas, hpi, all are pretty equal.
Folks immediately jump to slash 4x4, but 2wd is way more fun, I've got both, 2wd gets way more use. I really only run my 4x4 on slick surfaces to get all drifty, I don't think it's seen dirt in a couple of years. We build a track in the backyard every summer and run 2wd shortcourse truck and buggy all summer, it's a hoot.
What ever chassis looks cool to you, as long as lipo, brushless, and 2.4 ghz you will have fun.
Cheap chargers take forever, budget for a decent lipo balancing charger while you are at it.
Don't be fooled by chargers that charge multiple batts, all that matters is amperage. A 10amp multi charger will take longer to charge 2 batts simultaneously than a 10amp single will take to charge consecutively.