For me, if you your tank have high bioload, a number of FISHES, a skimmer is a MUST. I love red sea prizm skimmer, very stylish and neat. =]
My new nano 1ft cube acutally was suppose to have a skimmer, but the bloody tankmaker made a mistake and didint follow my intructions. But I reflected and realise that I dont need one becos my tank is oging to just have Corals and loads of inverts. i'll post pictures of my tank soon