I really think that the creation and addition of Cruley Bear has really made the character come a long way. In fact, funny everyone mentions Elmer Fudd... I say his original character took after him (or just as likely Yosemite Sam, in his fits of rage) just for the fact he was basically created to always be annoyed with Goldilocks's antics... which really made him a flat character. I think the turning point was dropping Goldy and making him Telly's best friend. I still feel the character's rise to popularity had a lot to do with David wanting a main character to perform on the show (long before he took over the role of Cookie).2. Baby Bear: Some people here have already mentioned his Elmer Fudd-like "baby talk" voice, which fits his age...but does more harm than good on a show that teaches the sounds of letters (among other topics). Besides the voice, his porridge-eating obsession shows a recent trend towards giving every Muppet a "favorite thing" gimmick and building most stories around it. Older characters grew out of being that gimmicky--Cookie Monster has actually appeared in a few segments that never mention food at all, and Oscar the Grouch has starred in a few episode plots that weren't centered on trash. I hope that Baby Bear, too, "grows up" eventually...
I really agree that too many old-schoolers say Elmo ruined the show. It's just too easy to say that, instead of looking at the disgusting trends towards children's (preschool) television during the 90's... I'm glad someone stated that in that way. Personally, I think the character lost a lot of likability for the reasons you stated. He went from a monster child to a child that just so happens to be a monster... and you really lose a lot of the character's child caricatured hyperactivity (like his selfishness displayed in the linking material for Monster Hits, or when he was telling reporter Kermit about his new ideeeeeeas for games). What I dislike about things like Elmo's World is you never see the character's personality.... even in Elmo in Grouchland and certain street scenes we can see Elmo's flaws and how he copes with them. And it's a darn shame he spends more time talking about Birthday cakes not wearing suspenders, since Kevin is such a talented performer... his outside of SS appearances are a LOT funnier and better than anything in the show. I especially like how he's almost a pervert.... (like in Scrubs... "Is she your woman?")Elmo: He's not the main reason for Sesame Street's deteriorating, believe it or not. (For that, I blame the Workshop's financial problems and the loss of so many original performers and writers.) Still, Elmo has evolved from a cute, playful friend of the gang to a hyperactive figure who thrives on attention--I miss the days when he was an equal to the other Muppets, not a superstar.
Okay, I'm not HUGE on Sesame Street, but I know enough to pick out the bad characters:
Elmo- I don't completely hate him, but as mentioned before, he's taken over Sesame Street. I would much rather see more Cookie Monster, Bert and Ernie, and all those guys.
Telly- Again, I don't completely hate him, i actually rully love him, but sometimes he gets super annoying.
Murray Monster- Sometimes I just wanna clock him in the side of the head.
Mr. Noodle- I know he isn't a puppet, but I hate him with a passion. He is the worst thing that has ever happened to Sesame Street.
I actually see those kinds of characters as similar to Blue's Clues and Dora. Kids most likely already know the answer (since they do have lives outside of watching TV!), and watching the bumblers just drills it in further and lets a kid feel important (like when they answer in class).Mr. Noodle is as pointless as the older bumbling human characters who demonstrated the wrong way to do things; how many old-school Sesame fans learned that much from Buddy and Jim, for instance? Even with an obvious-looking joke context, children that young may end up getting the wrong idea and copying the Noodles--simply because they don't know any better.