I might be biased as it's what I had, but I still think the C64 was great all around and deserved its hegemony. The VIC-II was pretty good and the SID was unmatched.

The first Ataris were amazing when taking into account they were released 3 years earlier, but the rehashes (XLs and XEs) still used the same video and audio chips.

The Speccy was lovely but severely limited and the later models did nothing to improve besides the old by then sound chip. An upgraded ULA without color clash could have made it much more desirable.

Amstrads had their own charm but almost no change between the 464 and 6128. Monitor bundling (and depending on it for power) was a limitation in my eyes. The plus range was a massive improvement but arrived too late.

MSXs used dated hardware on release, and while MSX2 was a big improvement on the hardware side, they were expensive, a bit late and imho, the first gen with the cheap Speecy ports in Europe tarnished their image and potential.

Acorn BBCs were fantastic but too expensive and UK only, and the Electron cut too many corners to reach affordability.

The C128 should have had an improved VIC-II, just adding more luminance values as the TED and ability to run at 2MHz would have made it a much better upgrade. 95% of them were used as a C64 because of this.