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.
Get the HTC one M8, its the phone i currently have. IMO its the best android phone avalible right now (not counting the one plus one). You may want to wait and see what the One M8 prime ends up being.
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.