Where would you rank the eponymous Sheep in the City, the lambs from that U.S. Acres cartoon/comic, and the protagonist from Ringing Bell (Chirin no Suzu)?

That's a very good question, and to be honest, I don't know the answer. Sheep are one of my least favorite subjects, so I have not devoted a lot of time, nor hard-drive space, to crafting a properly-researched list.

However, I can tell you that all of those sheep would be above Lamb Chop, even Bo and Lanolin from US Acres! In fact, Bo and Lanolin were the first sheep to spring to mind when I was thinking about Lamb Chop's place within the ontological hierarchy of fictional sheep; "Lamb Chop is so lame" thought I "that even the sheep from Garfield and Friends were better". That's pretty harsh, particularly since Lanolin was arguably the worst character in any Garfield media (the proverbial "worst of the worst").

If I had to rank them off the top of my head, the best sheep would probably be:

Lammy, Chirin, Fluff Pendelton, Babe, Shaun, and Sgt Woolly Pullover. (Lanolin, Bo, and the various Serta sheep could fight over the final four spots; wouldn't really matter, since that'd be enough keep Lamb Chop off the list anyway)

Adding to the list, there's Moa from Show by Rock!, Dipper doing the Lammy Dance, the exploding sheep from Worms, and the sheep that gets blown up in Bad Taste. I'm pretty sure there are some sheep-based Pokemon and Digimon out there, too.

Really, we could make a top 20 list of Best Sheep and Lamb Chop still wouldn't be on it.

Oh, yeah! Super Sheep! How did I forget him?! If each of the sheep-based WMDs (Sheep, Super Sheep, Aqua Sheep, Sheep Launcher Sheep, and French Sheep Strike) got their own entry, Lamb Chop'd be off the Top 20 for sure.

Which is really saying something.