Good website search engines?

Read: Free, no installation required, no ads, no gimmicks.

So I wanted to create a site at work with a lot of documents and stuff but I also wanted to make it easy to search through. I pulled up a couple things online that might be able to do the trick.

The 3 that looked interesting and could possibily fit my criteria above were:
Pico Search
Atomz (Web Side Story)
Free Find

So I tried the first one because it looked like it was in it for the money (so should work) and yet didn't look ad/commerce filled (so no extra crap). (Okay, I also liked the name. Quiet, you.) That said, it's not that strong a search -- but we all love pico so we'll forgive it. :) Anyhow, I put pico search on my 0x002a.com site for testing. The bad news is that my site isn't that easy to search/index since my primary content is in images without comments and the rest of my text content is either on the main page or in the database (forums and stuff). Doh. That said, better than nothing and oh well -- live and learn :)

So my question to you guys -- do you know of another site search engine that's easy and free to use? And/or do you recommend one of these?

Thanks! :)