These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Let's just save you all the trouble and say the music in every game. All of it. You'll have a hard time finding a piece of music in this series that isn't pleasing to the ears according to most fans.
Ensemble Darkhorse: Vanessa. When she debuted in 4, Vanessa was one of very fewAmazonian Beauties with a tough attitude, and had a fairly dark skin tone, making her very unique among female fighting game characters.
Broken Base: However, many other players apparently found these unique qualities unattractive, resulting in Vanessa's skin getting bleached, losing some of her muscle mass, and her tough attitude and voice getting toned down, all in an effort to make her less intimidating and more attractive. At the very least Vanessa is still the tallest, buffest, and most tanned lady in the series, and certain customization items can give Vanessa back her dark skin and muscles.
Polished Port: If there's anything the console versions of the various versions of Virtua Fighter 5 are known for, it's two things:
They look prettier than their arcade counterparts.
The online netcode is considered by even the most casual fighting game fans to be the best netcode for fighting games out there, with practically no lag except in the most extreme conditions.
Porting Disaster: The Sega Genesis port of Virtua Fighter 2. Made worse by the fact that inevitably when porting Virtua Fighter 2, this is the port Sega uses, ranging from online game services like Gametap to iOS, both of which are easily capable of handling 32-bit graphics and gameplay.
Self-Fanservice: A strange example in that this is used to revert a canonical design change between games. In her VF4 debut (and in Virtua Quest), Vanessa (see above) was shown to be dark-skinned and rather buff, accentuated by her wearing only a sports bra and shorts as combat attire. Her first costume was swapped out for a differently-colored version of her far less revealing special forces uniform in Evolution, but the real point of contention came in 5, where Vanessa suddenly lost most of her muscularity (the same thing happened to Sarah, though she wasn't quite as muscular as Vanessa to begin with) and had a progressively lighter skin tone (think Storm). While some fans originally complained that Vanessa looked mannish in 4 because of her physique, many more disliked the unexplained changes for 5 and continued to portray Vanessa in fan art as she appeared in the previous game. Sega AM2 must've caught wind of the Internet Backdraft, as Final Showdown has customization items that bring Vanessa's skin color and build more closely in line with how they were originally.
That One Attack: Jacky's somersault. It does insane damage on a counterhit, and it's a very easy move to execute. Many players tend to throw out this move, even though it's incredibly unsafe on block and can be reversed by Akira and Aoi.
Woolseyism: The English dub of the anime has a lot of these, making some jokes work better in English, adding in some extra funny lines, and making characters like Jacky and Pai more snarky.