I agree with the previous comments on HDTracks' version of Van Morrison's Moondance. It is one of my favorite recordings - not that the original was any slouch.
Being a 90s kid, that's where I started. These are all HDTracks files.
Counting Crows, A Long December, 192/24
Highly recommended. The individual instruments sit apart from each other much better, particularly the ones with treble overtones, like the mandolin and accordion. It also sounds slightly warmer than the CD; probably because they kept the tape hiss in, rather than running noise reduction. A must-buy for fans.
Natalie Merchant, Tigerlily, 96/24
One of my favorite records, but not a great version. It's clearer, but with a clear pair of speakers, particularly a forward sounding pair, there is occasional distortion in her voice. It's especially bad at the end of My Beloved Wife. Do not buy. In HDTracks' defense, I wrote them to tell them this, and they issued me a credit - but it's still for sale.
Soundgarden, Superunknown, 192/24
This was the first album I bought myself, years ago. So it holds a special place in my heart. That said, I'm mixed on it. Their music just doesn't benefit a whole lot from higher-res versions. There are a few songs from the second half of the record that do, but most sound just ever so slightly better, with a little more dynamic range on the top and bottom. Buy if you're a fan, pass if you're not.
Smashing Pumpkins, Mellon Collie, 96/24
This is the high-res alt-rock record to buy. I haven't got them all yet, but I'm sure of it. The recording quality is fantastic, and really takes advantage of the extra data, particularly on all the power ballads. Tonight, Tonight sounds holy crap awesome, as does Porcelina, and the other similar songs. The heavy songs are much better for workout music than the CD versions too. A must buy. Worth noting though: the file naming is all screwed up. You'll have to manually rename everything and create new folders to get it to show up with your other Pumpkin tracks, or even play in order.
That's it for now. I think my next purchases will be Tea for the Tillerman, and perhaps In Utero. I've been looking for a version of Exile on Main Street too, especially since my Dad swiped my 180 gram reissue.
I suppose it's only fair, considering how much I've swiped from him over the years