Ok, so I've decided after getting a negative rep for saying that people should STFU about vista sucking, I've decided to defend me stance here (And possibly open myself up to more bad reps, but whatever.)
First, some background. I have been running vista ultimate x64 for about 6 months now, I have LOVED it as an operating system. Before I bit the bullet, however, much of the negative rep it received made me fairly nervous about using it. In fact, I almost didn't!
So here is how I would like to proceed, I'll address the most common complaints that I've read about vista and then answer questions or "Vista sucks because of X" statements. I won't respond to "Vista sucks because Microsuck made it!" type responses. As that just screams "Im a fanboy that can't come up with rational arguments".
Vista is a memory hog
This statement has to be the most common vista complaint I've seen. So obviously you have to ask the question "Why is vista using so much memory?" The answer, simple, Superfetch. Vista, much more then XP did (and yes XP did do this to some extent), loads up frequently used programs and files into memory. It does this so that when you click on the Icon, the program seems to launch much quicker.
So what if you want to run a program that uses more memory that is available? Simple, vista frees the superfetch memory and allocates it to the program requesting it.
So my question to those complaining of this, would you rather your 8gb of ram sit there empty, doing nothing, or would you rather it provide a performance increase by pre-loading frequently used data?
Vista is unstable
There is not much to say here other then that is a complete lie. Vista is EXTREMELY stable. I've experienced fewer crashes with it then I did with XP (and I experienced very few crashes with XP). So where the problem? recent studies showed that 90% of all vista crashes where caused by nVidia drivers. Not exactly microsoft's fault. They gave nVidia and several other driver manufactures tons of specs/SDKs about how their drivers would work, and yet the companies sat on their duffs.
Vista doesn't support X
You know, this one sucks, but eventually microsoft had to stop supporting programs made for the 1980's. Most of them will run with a program like DosBox if you really need it to. Its Ironic because this complaint leads to the next. Much of vistas support issues where fixed with SP1. I, myself, haven't run into a program that vista couldn't handle out of the box.
Vista's Too bloated!
My response, Well, of course. Chances are the same person that complains that vista doesn't support X will also complain about how bloated it is. Well, you can't have it both ways. Vista supports far more hardware straight from the disk then any previous version of windows has. That support comes at the cost of bloat. Not only that, but the added features and background services that make the system run smoother and cleaner aren't magically free. So vista resideds in 1GB of HD space, and DOS only took up 1 MB, So what? Are you saying that $.01 you spent for the gig that Vista occupies is really that important?
UAC sucks!
Yes, it does, it also makes the computer much more secure. Vista infection rates are the lowest of any MS operating system ever. Sounds like UAC is doing its job well. Not only that, but you have the option to disable it if it really bugs you that much.
Those are the main points I've seen brought up about vista sucking. I'll be happy to address any other that you are willing to bring up. I'm just tired of seeing the childish bashing of vista. It started with a media propaganda hatred for MS and ended with the now moot arguments we see today. The same thing was attempted with Win 7, however, microsoft seams to have effectively smooshed that with their open beta program for windows 7 (because enough people are able to say STFU when a online reviewer talks about how terrible win 7 is).

