I have the HTC One M8 and I love it so much. Dual frontal speaker and the best frontal cameras compared to other phones if you're into that. The metal shell makes it very durable. I have no issues with battery life so far and I can play FFIX using emulator for about 6-8 hours before it dies. On standby, it'll last me a couple days or 2 days with medium usage. The HTC One E8 was recently announced and it looks like it'll be much cheaper than the M8 with its polycarbonate cover and other small changes so you should follow that if you're on budget.
My girlfriend has the Galaxy S5 for about 3-4 months now. She recently just broke the screen with spigen cover/tempered glass screen protector just last week by accidentally dropping it. Anyways, I played with it and I'm not fond of it. I prefer the HTC UI and Super LCD more. The fingerprint definitely needs some work because sometimes it would take me 3+ tries to unlock it.
I would love to get my hands on the OnePlus One. Unfortunately, I already bought the HTC One M8 before I even heard of the OnePlus One. Still, no regrets.
Thanks guys, I think I might just go for the 1+1 just because it'll be a worthwhile investment for me for the longterm. G3 is a solid contender but too expensive.
If anyone has bought a oneplusone and has a spare invite, I'd appreciate it