Well, saying opened cans are "better" is kinda a subjective thing. There are plenty of fantastic closed cans. It's just they have a different sound signature. As a rule of thumb, closed has more bass, where opened has slightly less, but more air. That's very general though...and not very in depth.... anyway, it sounds like what you want is an opened sound minus the leakage. For that, I highly recommend the Shure SRH-840. They run around $150. They have a relatively balanced sound signature, so that should work well for your situation (Sound sig: slight mid emphasis, mild mid bass hump. pretty much unnoticed for casual listening...). Balance will let you cross genre. The sound stage, for being closed, and at the price, is simply phenomenal. They are fairly easy to drive, do no amp is absolutely necessary. As well, the leakage/isolation is wonderful. I use them to listen while my family watches TV right behind me....i can't hear a single explosion....oh the wonders....anyway, i highly recommend them. Any questions, feel free to pm me.
It sounds like you know my future... my noisemakers are 5,4, and 1.. I will check those 840's and the CAL!'s out in the meantime.
I do have a question about the 840's though - one of the recommended links in the sticky was for the innerfidelity website, and he had replaced the 840's with the UE6000. The UE6000 is $10 more than the 840's so wondered what y'all thought.
If the open cans would be a good supplement to something like the CAL! in the $150-200 range, I was eyeing the K167 TIESTO or AT ad700's. Unfortunately, we don't have anywhere to actually check them out in person.
Go for the AD900. They are featured in the Flagship thread and are one of the top three best buys according to the author.