You don’t say how much you are willing to spend? In general, you need to spend $1300 or more for a descent Hardtail and $2000 or more for a descent Full-sus. Check out Trail Talk MTB on Youtube which does some very good compilation reviews of “best value” bikes.
Here are some Hardtails I like.
Giant Fathom 29
Vitus Sentier 29
Specialized Fuze 29
GT Zaskar LT 29
Rocky Mountain Growler 29
Here are some short-travel full-sus bikes I like.
Giant Trance 29
Specialized Stumpjumper
Here are some longer-travel full-sus bikes I like.
Vitus Mythique 29
YT Jeffsy 29
Commencal Meta TR 29
If I had to pick one bike which I consider to be the best value and the best beginner bike, it would be the $2250 Giant Trance 3. This bike comes with very good spec for the money and is just a good all-around trail bike that really doesn’t need any upgrades and you could ride this bike for years without needing to change a thing. Even though Hardtails are cheaper, I think, in the end, you’ll have more fun riding a full-sus bike. If you buy Hardtail and you like Trail riding, you’ll probably end up buying a full-sus bike before very long anyway.