Honestly, I've had less problems with Win7 then I have with any other win based OS... except for maybe 3.1
Win95 wasn't that bad, but it really drilled into your head what a BSoD is.
Win98 made it better and offered a lot more functionality (the quick launch comes to mind), but it could just be my inexperiences with operating systems at that point. Hell i was 14 and using AOL at that point. That was also when I downloaded everything and used Nortons *shudder*
WinME had so many great features that was incorperated into Xp and refined. It had a dedicated video viewer instead of I.E. displaying everything.
Now xp is when it gets confusing. Xp sucked when it first came out, it really didn't get too stable until sp2 from my experiences. One major difference though is Xp was built on the NT kernal where as win 98 was still running on the old 98 kernal? i forgot what it was called. I know that 95 was pretty much just a GUI interface for DOS.
Anyways, When vista came out, it was a brand new kernel again. This time though the kernel wasnt refined through Windows 2000/windows nt like it was for XP so it was the poor child trying to play catchup. Plus vista was a resource hog, I don't care what anyone says, Win7 really slimmed it down.
Now I am a faithful win7 user and recommend it to everyone... with a moderatly powered pc. Xp as of sp3 is about as stable as one can get. Win7 though has all the advanced functionalities that come at a price. That price being the need to iron out details.
I'm in robbs case though. I use my pc for everything all at once. As im typing this i have adobe premiere pro running while downloading the beach boys tv movie while watching a coaster video while syncing my zune while having aim, yahoo, msn, skype, xfire, wootalizer, google talk, hamatchi, firefox and whatever else i got running.
Sure my computer takes about 15 mintues to boot up, but on my barebones laptop i use as a media pc, it boost from post to desktop in about 2 minutes, incluing the time it takes for me to log in.
Alot of the problems though stemms from people doing upgrade installs as opposed to fresh installs/custom installs. It's always better to start with a clean slate when upgrading an operating system, especially Ubuntu, then try to pave over the old crap.