Vista had some teething issues, manufacturers produced products that were under-spec and stuck vista on it, and the changeover from 32bit to 64bit was handled badly.
There was nothing inherently bad about Vista, except people experience alot of problems. Service pack 1 basically fixed most major issues.
Windows 7 was beautiful from day 1. Everything in Vista was fixed (it's the same OS, right), it had a few new features. The interface was more polished.
Windows 8. Heavily Optimised for newer/current technologies. It performs faster than windows 7. It's quick, it's beautiful. It has the worlds most useless Graphical User Interface for PC's. It's basically useless for anyone that intends to WORK on their PC, and when I say work, I mean serious email, internet and Office type applications.
I'm dreading my next (work) PC upgrade.
My Home PC, I can just butcher and upgrade parts and keep windows 7.