Sennheiser's are great, if not a bit expensive...
the Sennheiser HD 25-II is like 200 euro's.. but it's fantastic!

I have got some seinhouser in-ear earphones, they are amazing, though I do not know if they do over ear headphones

I have a set of the Bose noise canceling head phones though I can't tell you what model they are I can tell you they are great.

Their a few years old and they go through batteries fairly quickly but I love them. I use them all day at work and to keep me from spending a fortune in batteries I just keep a battery charger at my desk.

As far as the noise canceling goes, I can still hear people talking but all the other little stuff just completely goes away. There times though when I don't even notice people talking to me with those on though.

Bose are a bit overpriced, but they are nice.

My friend has the best headphones ever, but I can't remember even the brand name...I'll post later tonight.

@Commando
I tried looking it up.
The price is nothing to complain about.
But it requires 3 headphone jacks, which unfortunately, my laptop and CD player doesn't have.
Reviewers say it also lacks bass.
Thanks for the heads up though.

I'd generally recommend headphones from AKG, my favourite company for headphones.

I bought the AKG K 141 Monitor four times during the last 20 years. They were known as the most used headphones in professional music studios. As the K 141 Monitor is officially not anymore available, I recommend  the successor K 141 MK II.

Noise-cancelling DJ headphones from AKG: K 181 DJ or the cheaper, lighter K 518 DJ.

Guys thanks for the help but I have to leave for practice.
I'll read it when I get back.

I did a quick research on the website of my preferred hifi magazine. According to this magazine the best noise-cancelling headphones are at the moment: 

Sennheiser PXC 450  audio-technica ATH-ANC7 Bose Quiet Comfort 3 (which you already mentioned)

By the way: Grado's iGrado are by far the best headphones available for portable devices according to this and other magazines (not noise-cancelling of course). Worldclass headphones for 80€/49US$. Interesting...

I agree with Dallinor....get Skullcandy's! They really do block sound....

I have skullcandy's too. I have the SkullCandy Full Metal Jacket with the mic on it, for use on my Blackberry Curve. I love it, I can't stand no other type of headphones but the in-canal headphones (the one that u kinda "screw" into ur ear) because they never stay on my ears. Great quality, it really does cancel outside noise. If u r not getting it for the mic like I did, I suggest u go with Dallinor's pick.