Well look, I'm not you. I can't predict what will sound pleasing to your ears. Everything Trujunglist said above is accurate and I agree with 100%. At the end of the day he prefers the HD25 and I prefer the M80. There is no 'best' between the two. You really need to listen to the HD25 and get back to us so we have a point of reference. When listening to the HD25 keep this in mind; The M80 has a noticeably more laid back high frequency (treble). The M80 has a fuller sounding mid range. The HD25's bass thumps slightly harder and decays quicker than the M80 which is why it's described as fast. The M80 bass hit respectably well, especially considering it's size. To my ears the M80's bass sounded more textured and picked up the lower bass frequencies more than the HD25. I imagine the most likely criticism you would hear about the M80 is that the highs are too laid back.
P.S. The German Amazon does not let you return items you are not happy with for a refund??
so... i went to listen to the hd 25, it sounded nice, the problem is that i felt that the bass was a bit too weak and there was too much treble, it was a bit to clear. i think i want more balanced, more bass but not to sound like beats which has a bad sound quality...
i listend without an amp to some rock and pop with ipod touch at about 80% volume. are the m80 really the best choice for me with a budget of about 300$? i dont care how it looks, i want it to be comfy and sound like i described here