I would say Orochi is still worth getting because 95, 96, and 97 were really only circulated on the Saturn/Playstation 1 in Japan. (Although 95 made it out in the US) Also, the games on the Saturn/Playstation were close but from what I have read they had to remove some frames of animation.
Garou, Last Blades, Orochi, and Nests(PS2/DC ports) all have relatively the same level of sprite flicker. However the emulated originals on NESTS are a lot worse than those on Orochi.
As for Garou, Last Blade 2, and NESTS(99,00,01) get those all on Dreamcast as imports. If you combine the superb NEO ports on the Dreamcast, with those on the PS2 you can cover a lot of ground.
One thing I want to make perfectly clear is that the games that do have sprite flicker, don't have scan lines, and thus, look jaggy. The way to effectivly make a game look better and more complete is to use scan lines. Unfortunatly a lot of companies use crappy blur techniques, and stupid pixel smoothing to get rid of pixelation instead. Remember pixels are not a bad thing, and I don't understand why people feel the need to get rid of them. (As a side note: most games that do not have scan lines, tend to have sprite flicker.)
One such example would be the travesty that is KOF2001 (US/PS2) release. Where they took all of the background sprites, blurred them out and recolored them. Some dumb people seem to thing this "fixed" a flaw, which some people seem to insanely think are pixels. All it did was trash and ruin the games background art. The funny thing is you get to see what the game should have looked like when you pop in the KOF2000 disc which has proper scanlines, no sprite flicker, and backgrounds that were not tampered with.
I am actually not 100% sure what port version the NESTS 00/01 are. They might be DC versions running on the PS2 with fake low res (which is a prime cause of sprite flicker where they scale the graphics slightly to a resolution which they didn't originally support). These also may be the original Japanese PS2 ports, which I don't own to compare. What I can confirm is that the 3 primary games on NESTS are not NeoGeo originals and KOF99 is 100% for sure the DC version because of its 3D backgrounds.
In some cases you would want to choose a game with sprite flicker over another game for this very reason. One such example is SVC Chaos on the PS2 vs the Xbox. The japanese PS2 import is very crisp, and pixel precise. However there are no scanlines so it suffers from some sprite flicker. The xbox version doesn't have sprite flicker, but the developers BLURRED out all of the textures in the game, and it basically raped all of the backgrounds because of it. This is noticable when running both games, on each system, pausing them and then bouncing back and forth via an s-video switch box.