I have decided to get into this through the back door (which as all of us Mario fans know is the much easier option) by way of the WiiU VC port of Mario 64. Hey, emulation is emulation, right? There are a few notable priority issues from time to time (e.g., Mario appears in front of trees in places where he probably shouldn't) but it overall is still pretty great, and while I know the WiiU VC has a reputation for washed-out colors, fortunately there's no loss of vibrancy on my TV.
Bob-omb Battlefield is such a delightful statement of purpose, even if the mission where you have to grab coins from the cannon is hampered by the low object draw distance. I've 100%-completed the missions for it, Thwomp's Fortress (also quite excellent, though the 3 easy stars make it a much less memorable level), Snow Man's Land (a pain to navigate if you don't know about the warp, but it's easy to stumble on accidentally), and Big Boo's Haunt (mostly quite fun except for the bit where you have to kill king boo on the roof -- that bit with the double jump to the wall kick is unpleasant and not helped by the fixed camera angle; same with actually getting to the top of the roof to reach the star).
I've gotten partway through Shifting Sand Land too, and that level is as un-fun as I remember. The first star is fine since it's so simple (just get to the other side from the closest spire by a long-jump next to the pyramid's main entrance), as is the pyramid alcove star, and heck, even the one where you just climb inside the pyramid (probably the most fun one of the bunch because there's no instakill sand inside it!). I spent an inordinate amount of time trying to get the 'stand on the 4 pillars' star, because those pillars are fiddly and I think you have to select the star in question to get the top to pop off properly. Still haven't done the 8 red or 100 coin stars, nor the pyramid puzzle and I'm not particularly looking forward to them.
I already have 38 stars (got the wing cap, vanish cap, dark world, first Mips, both slide, and one Toad secret star), so I don't actually need to do any of these basement levels other than Bowser's sub at this point, but I want to make a serious attempt at most of the game, as it's been a while and I've played enough newer 3D Mario that I want to take it seriously. As someone who never really liked how the game controlled, I think my experience with newer Mario games is helping a lot, because while the jumping still tends to be pretty fiddly it's much less frustrating than when I was a kid.