Do you have any specific reasons, or will this just be a listing thread? It's okay that you don't like him and everything, but the conversation will be a lot more interesting if you state the reasons why, the reasons why the character doesn't work.
But I'll continue the list with some other characters...
Elizabeth and Little Murray Sparkles- Okay, so maybe not Murray... he's a cute puppet and everything... but the whole point of the character is to say how cute and lovable her cat is.... something about it rubs me the wrong way, since she comes off extremely flat as a character. Somehow I wish the cat would have been somehow displeased with her... sort of like how animals react to Elmyra of Tiny Toons... or somehow like the cat think's what she's doing is undignified. Plus, the whole overly proud of someone or something doing nothing special has been taken by Humphry and Ingrid, who did it much, much funnier.
Rodeo Rosie- It's killing me to pick on an old character... especially since I like how the character looks, and her overall design... but
her intoduction skit showed showed that she was abrasive, bossy, loud, and came on waaaaaaay too strong. Her entrance is random, too... and somehow comes off exactly like the Poochie skit from The Simpsons.
The Two girls on Monster Clubhouse- lacking personality at every turn. It's such a shame Stephanie never had any major characters that got real developement... she is highly talented, but she never had a character of which she found her voice. And when they were close, she left the show, or the characters were phased out. That said, I LOVE the 2 guy monsters, Narf and Mel... Too bad they were used exclusively in a bad segment.