Recommend a filter

[waterbear]

Having owned cartridge filters on a spa and now a pool/spa combo for a total of 7 years now (and even longer on large salt water aquariums-they are basically the same-- so I am biased) I can tell you the trick with cleaning them and not getting wet and dirty is to NOT wait until the pressure rises but do it once a month. A quick hose off with a garden hose nozzle set on stream or ribbon (make sure you start at the top and work down the pleats) and the cartridge is clean. Mine takes about 10 minutes total and that includes cleaning out the pump basket and repriming the pump. Maybe once a year I have to soak the cartridge. This regular attention will also help prolong the cartridge life.

The pro and cons of various filters in a nutshell:
DE filters out the most and really polished the water but is probably the most work.
Sand is the easiest but the least effecient at filtering small particles.
Cartridge approaches DE in it's ability to filter small particles and actually will filter better when slightly dirty (which is why some people add a bit of DE powder to them) but the cartridges have a lifespan of about 5 years and can be costly to replace (mine is $110-$165 currently) and if you wait for the pressure to rise they can be a MESS to clean!
I will qualify what I have said by saying that I have never owned a DE or sand pool filter but I have friends with them and I have had to help my brother break down his DE more than once.