For myself I think a lot of people tend to believe that with better equipment they would be better Photographer's, for most of us, I don't think that true. I think the right answer was from Greybeard. Keep the one you like most. I got a 55-300 just for shooting dog's casting off and bird dog field trils. My 70-200 was just a bit short and there was no 18-300 them. Today I still have the 55-300 but my most used lense on the DSLR is an 18-200 Tamron, It simply works for me! I think the best way to determine what you want is get what you think you want and try it. You'll find something that will take you in. Down side is that it could get awfully expensive that way! I met a guy a while back that had an 18-300 Nikon on a D7000, same camera I have. Wish I'd have looked through it! But we were out looking for a couple bald eagles and from where we were to where they were was a long way off. I had on my 18-200 Tamron because I really like that lense, it grew on me. I've got a 150-500 Sigma and left it home, go figure! Truth is the 150-500 wouldn't have worked either, simply not long enough! But that guy's 18-300 Nikon wasn't long enough either but I wish I'd have asked to look through it ust the same. Try the lense's you think you might like, not for just a minute but several days and one will pick you! Start with the one you can afford and work your way up! And be honest with yourself about your own short comming's, bad picture might not be the tool but rather the mechanic!
Getting back to the 150-500 for a moment, I got it thinking I'd be ready for any wild animal I wanted a photo of. Boy was I wrong! Thing does a good job when I do it right but it simply never made up for my short comming's. An animal 500yds off is 500 yds off and 500mm just isn't much to get it in with! Cost me about $900 I think it was to learn that lesson. But even though I learned it by trying it, and at that time I had the income so it was no big thing.
Another thing I found with the Panosonic I recently got is I like the lense coverage with it, 25-250! If 25 is to long, I need t get closer and if 250 is to short most likely I'm gonna have to get more than a little closer! The bottom line is probably if your using a single focal length prime lense your never gonna be in the right spot and are going to have to move some. I'd think the 18-300 would be the best choice but probably might not get as good a picture as something shorter, everything has it's drawbacks! On the up side, while you might not get as good a photo, you can still get a photo!