Most useful Pokemon
Which are the most useful or important Pokemon to power up in the current meta, and prepare for legendaries?
Please rank them.
1: Machamp double fighting (counter to Blissey, Snorlax, Tyranitar, Lapras)
2: Tyranitar B/C or SE (counter to most legendaries)
3: Golem (double rock especially, counter to some legendaries, also great against fire types)
4: Dragonite anything/HU or OR, DB/DC (great generalist, HU good against Machamp
5/6: Alakazam/Espeon anything/FS (good against many raid bosses, especially Machamp)
7: Rhydon MS/EQ or SE (good against fire, EQ good against electric and poison)
8: Vaporeon WG/HP or AT (good against Arcanine, Flareon, Rhydon, Golem, future Moltres, good generalist)
9: Flareon FS/OH or FT (good against Venusaur, Exeggutor, Scizor, Steelix, future Articuno, good generalist)
10: Exeggutor anything/Solar Beam (good against Vaporeon, Rhydon, Golem, Lapras, Donphan, good generalist)
Any more?
Answers
No, it's not. He is trolling. In the current meta, having good Machamps with Counter/Dynamic Punch is extremely helpful in dealing with a handful of raid bosses. Definitely invest in one or two. For the legendaries, assuming we're going to battle them, any heavy-hitting rock type such as Golem and Tyranitar will be good against them. Overall though, I think it's good to have a diverse selection of meta Pokemon available to use, there is no reason to be ranking them with the way the game is in its current state. Different Pokemon have different roles.
1 benefit of Blissey is that she will stay in gyms for days, as you mentioned. Why is this a benefit? Because if you're trying to accrue points towards a gym badge, having Pokemon in them for extended periods of time will make that process much easier. Additionally, you'll make some progress on the "Gym Leader" badge once your Blissey is finally kicked out, if you care about that sort of thing.
I'd include TS/TB Jolteon on there. For some reason, people keep putting Gyarados in gyms, and it takes a matter of seconds with a good jolteon to knock them out.
Also, if you lack good grass (hehe) then he's serviceable vs vaporeon (and other waters).
As a comment on the OP list, I think Rhydon (too slow) ranks too high and Eggy (good generalist) too low. But pretty good otherwise.