Where do you typically ride and how aggressive are you? Unless you're all about XC racing, shuttling up or lift-access at the ski resorts, I'd recommend a good full-suspension, trail or all-mountain bike that can do 90% of what you like. Something with 120-130mm travel in the back and a 130-150mm front fork. And you definitely want a dropper post. I'm partial to 29ers (but I have both 29ers and 27.5+).

If you're looking for a bike that climbs well and can handle some pretty aggressive DH, I'd recommend:
High end: Pivot Trail 429, Ibis Ripley, Revel Rascal, Yeti 130 or Santa Cruz Tallboy
Value bikes: Canyon Neuron, Giant Trance, Transition Spur

I'd recommend keeping an eye out for newer (last 2 years) used bikes on pinkbike.com, KSL, Facebook Marketplace.