Alright, I lied. I'm going to post four more rankings, for the last four members of the SacredFireNegro's walkthrough. (I was going to do Swirlix for shofu, but I didn't know if the Whipped Dream was available to evolve Slurpuff or not.)
(PLACEHOLDER)
Samurott for C+ Rank:
Samurott has a nice Attack and Special Attack, but that's pretty much it. He does gain Megahorn, Aqua Jet, Aqua Tail, Revenge, Surf, Hydro Pump, Swords Dance, and Encore, however. There's also Night Slash and Air Slash from breeding. Samurott is an average Pokemon, honestly, having two Abilities that don't quite stand out. He is good for certain battles, like Marianette (with Revenge). He's also decent for any battle against a Leader he has a disadvantage to. All and all, Samurott isn't the best, but he can manage to do some work.
Unfezant for C Rank: Unfezant is one of the regional Birds, but is also one of the worst. It has a great Attack, but only Facade and Sky Attack to help it. It also gets Tailwind, Swagger, and Taunt as a plus. It's usable for the early leaders, especially Keta, but later, there will be better...
Mr. Mime for C Rank:
Mr. Mime has a nice Special Attack and Special Defense, as well as a nice choice between Abilities. However, it doesn't seem to have the moves to support it. Psychic is its best STAB, and it gets Reflect and Light Screen. However, that's it. No Fairy moves or anything. Mr. Mime can be useful for battling Keta and maybe Marianette, but afterwards, it's outshined by other Pokemon.
Roserade for A- Rank (Completely ignore if we don't have Shiny Stones yet; I don't know.):
Roserade has three great Abilities, an excellent Special Attack and Special Defense, and a decent Speed. It also has great moves like Giga Drain and Petal Dance as well as supportive moves like Toxic Spikes, Leech Seed, Aromatherapy, and Synthesis. Sadly, no Poison type moves... Either way, she's a beast for taking down most Gym Leaders, exceptions being Angie (duh) and Crawli. For the rest, she can set up Toxic Spikes and Leech Seed, do some damage, and heal. She's best in battles such as Valerie.