The DT-880 is semi-closed (read no isolation) but a decent value at it's price point.
I recently acquired and have been mesmerized by the ATH-W5000. I read mostly negative comments prior to trying it for myself. Fits me like a glove, superior isolation to the DX1000, deep soundstage, plenty of good bass quantity and quality. The sound is colored, but in a pleasant way to my ears on my system.