There weren't that many all-time great platformers to begin with, so I think you can make an argument that the contemporary period wins, particularly if you weight aesthetic variety.
From the original era I'd rank these as genuine classics: SMB3, SMW, Kirby's Dreamland 2, Wario Land III.
From the contemporary period I'd rank these: NSMB Wii, Wario Land: Shake It, Super Meat Boy, DKCR, Kirby's Epic Yarn
Overall I agree that the original DKC series hasn't held up spectacularly, but they're still good, if not great. I never liked any of the Sonic games no matter how hard I tried to get into them. I basically detest Yoshi's Island. Most of the indie darlings that come out aren't actually that good. I did not love Rayman Origins, and suspect Legends is more of the same. NSMBU stalled out after the fantastic Wii iteration.
Mainly, though, DKCR and Super Meat Boy can stand up to any game of any era.