I will be buying my first "real" mountain bike. I don't want anything outrageous for my first bike. That will be my second bike! Something like, say.... a Litespeed Pisgah! So what is a good, solid first mtb that I don't have to modify the crap out of as soon as I bring it home to make it decent? I would like to keep it under $1000, preferably even under $750. Also, a hardtail will work fine for me. As for riding, I will be taking it on some pretty good trails, so I do need something rather durable. Thanks for any advice.

Welcome to the forums mbtjc! Lots of good stuff here, take a look around. You might look at this thread; https://www.bikeforums.net/showthread...&threadid=7491 .
It's in your price range and a really good bike. Just be sure and ride whatever you are looking at before you buy. Make sure it feels good to you. Good Luck on your purchase!

Or this thread:

https://www.bikeforums.net/showthread...&threadid=7033

Good Luck & L8R

Go get yourself a Giant Ranier. There really isn't anything out there that is competition in that price range for this bike. Good mix of LX/Deore and Avid disc brakes make for a killer bike at $750.

Also, try out a Fisher Tassajara or a Hoo Koo E Koo. The Fisher's have a drastically different geometry that some people prefer.

Also, check out www.harobikes.com their bikes are also very competitively priced. They ride well and come equipped with full shimano componentes, i.e. no generic parts!

L8R