The only one I've seen a significant amount of is the 90s cartoon due to having watched it as a kid and revisited it recently, though even without nostalgia the 90s series seems a lot better, despite the majority saying the opposite. From what I've seen, Spectacular Spider-Man brushes over his origin story until the Season 1 finale against Venom in a rushed manner and, thus, weakens his motivation by making it more about his job and love life than his need to protect those dear to him and not repeat his past mistakes. By the time of Season 2, SSPM just starts rehashing the same villains without many interesting scenarios, compared to the 90s series having decent plot continuity in its story arcs from Season 2 onwards and keeping things fresh with cameos from other Marvel characters such as Doctor Strange, Iron Man, Fantastic 4, the X-Men and Magneto.
Also, the 90s series looks way better. Buff manly meng >>>> knockoff Ben-10 artstyle. This is especially true for Venom, who went from looking like an intimidating, hulking monster in the 90s series to looking like some Druddigon-tier filler Pokemon design in Spectacular.
In many ways, it can be seen as comparable to the differences between the 90s Batman series and the 00s series The Batman; the newer series doing a few individual elements better, but overall not being able to compete when it came to a good art style, interesting scenarios or characterisation.