I have an eTrex20 (with the buttons torn off - man, that made me mad) and an Oregon 600. With my penchant for Custom Maps, the 500 tile limit of the 600 is really nice.
If I were on the market today, I would probably consider the newer eTrex models - maybe a 20x or a Touch25 (few buttons to tear off). I imagine with the smartphone being so prevalent, the dedicated hand-held GPS device will be a thing of the past soon...so I might grab me one before they disappear.