My wife just purchased a Katadyn Base Camp for my birthday.  I haven't used it yet.  It was $53.00 at Amazon.  It gets good reviews and real life testing gives the filter closer to 150 gallons vs. 200 before replacement.  

For 18 years, I've never used a water filter in Quetico.  It will be interesting to see how this effects my, uh uhm . . . overall constitution.  While I have never gotten overly sick from Q water I do have some theories.