Infected with Adware for the first time

After years and years gone by having the cleanest PC on the network (that’s right), an adware stop by and said hello :

Fake infection warning

See how my firefox window turned small? It was actually behind the warning dialog box at first, making a false impression of Windows warning. I pressed Cancel (of cource), and it took me into freewebscanner.com and again, the site do a system check and said that my system was infected.

Another false warning

And it even offered me to install some software, geez. Apparently AVG Anti-Virus Free and Spybot – Search & Destroy just not enough. Any suggestion for good anti virus/spyware? Anyone who reply “Ubuntu!” is gay