The M8 is a powerhouse, and an all around solid choice. If you are not real in to modding your phone but the bloat still bothers you the motoX and the Nexus 5 are amazing phones. Don't get the GS5, wife insisted that is what she wanted, great camera but the thing is huge cumbersome, and comes out of the box slowed to a crawl by the crap samsung puts on it (also touchwiz).
Linus has been able to touch a good deal of the phones on the market and has picked the M8 as his daily driver but not without a few gripes. (https://www.youtube.com/watch?v=1gnPdiE5kVs) For me, it would be the large "chin", i love my super skinny bezels and that would be just too much for me.
I'd still recommend the Note 3. Even with GS5, M8, and G3 out, I think it's still the best. Still has great specs, replaceable battery, SD card slot (I'm using a 64 gig), great camera, big beautiful screen, and tons of ROMs to get rid of that horrendous TouchWiz shit.