At first I thought off was the best choice since as many people here have said, "I know what im doing"
but then, I started using linux and began having a deeper understanding on why UAC is a good thing.
Thing is, by default, windows systems were more vulnerable than linux ones for different reasons, but one of the most important reasons is, the root account.
In linux, in order to change system files (say, what your windows folder is, and other stuff like that) you need root rights, to install/ uninstall programs, you need root as well.
This means that if you get infected by a virus, the virus can not access these files because there is a wall between its code and the files that wouldnt be there if root didnt exist, or in windows case, UAC.
This can be understood more easily from the debian distributions of linux, or more precisely, Ubuntu.
In ubuntu, in order to do administrative system tasks, you need to use the sudo command, which basicly is a more efficient way to getting root privileges.
UAC is what you could call, a way of implementing that sudo functionality windows-style.
If you indeed know what you are doing, specially if you share your pc with other people, the best way to go is to set up your system as admin, but then use a normal account for every-day use, and if you ever need to elevate your rights, UAC will be there to easily help you do it without having to log in as admin.
By doing this, your computer will be much safer from any new unknown threats, stupidity of other users and so on, all in all, its a more solid system of doing things.
Just as in linux anyone will tell you running as root all the time is dumb, running as admin on windows, specially without UAC, is dumb as well, in fact, quite dumber since the virus /worms/trojan threats are significantly larger in windows, and even tho you know what you are doing, sometimes, it can still get by.