Great responses. I'll add my 2 cents but keep in mind what PC747 said about what is good for one person may not be for the next.
I bought the G2 on release day. It has some great specs and I think LG beat the competition like a drum getting that phone out ahead of it's peers. It has a lot going for it. For its size (a little bigger than the S3) it has a fast chip, a big display, and a 3000 mah battery that last all day for me. But... I do not like it's camera for indoor shots. The GPS takes forever to lock unless you keep it on all the time. And no SD card slot or removal-able battery. The UI is very slick though, I really like how quick it responds to touches and I have a custom ROM on it that I really like as well as Xposed modules. It has its short comings but overall it's worth owning.
I also got the M8 on release. This phone has impressed me. It's fine stock, but even on Verizon I was able to S-Off and put a ROM on it. Battery lasts all day, great sound with the front speakers, SD card slot, metal case, fast chips, GPS locks instantly, and the camera is just fine for me. Hell, one of the first things I do when setting up a phone is set the camera picture to its smallest so I'm not trying to share huge files. The M8 is already set to where I set other cameras to with the added plus of having a camera chip built to take advantage of gathering light like that. It takes the best indoor pictures I've taken with a phone. The M8 is taller than other phones but if they could have made it shorter while keeping the narrow width and doing what it does, I'm sure they would have. This is my favorite phone next to my little Moto X mostly because of how quick it feels. Cool settings options too.
I pre-ordered the S5 even though I was not happy with the final specs. I've only had it a few days and I need to spend more time with it. Making it waterproof evidently forced them to increase it's width over the S3 and S4 and I don't need a fingerprint scanner... it has a good camera, fast chip, an SD slot, and a replaceable battery... but, it still has some Touchwiz lag and I think I like my MDK S4 better. But we will see, we don't have root yet and maybe it will grow on me.