I like google ads. Mostly because they're TEXT ONLY.
No blinky ads, no flash with SOUND (ARGH!!), no "SHOOT THE TENNIS BALL WITH YOUR LIGHTSABER TO WIN A FREE PSP!!!!" flash ads.
If you have adblock, you absolutely NEED to add this to your list:
*.falkag.*
because falkag ads and popups will try to install spyware/viruses/viruspyware/malware/soup onto your computer.