I submit Jebus for my second…
Nah. How about Malloy the cat-burglar?
D’oh! And to think I mutter to myself when other’s post duplicates… if there was an edit button, I’d change it to Robert Goulet (“Jingle bells… Batman smells…” )
Too many duplicates, I think we need a summary. As of Post #180:
Abbie
Abraham J. Simpson a.k.a. Grandpa Simpson
Albanian exchange student
Amber Dempsey
Apu Nahasapeemapetilon
Artie Ziff
Astrid Weller
Barney Gumbel
Bart Simpson
Bea
Becky
Bleeding Gums Murphy
Blinky the Three-Eyed Fish
Blue-Haired Lawyer.
Bob, the guy who runs the RV lot in Springfield
Brandine
Buddha
Captain Lance Murdock
Carl Carlson
Cecil Terwilliger
Charles Montgomery Burns
Chief Wiggum
Chuck Garabedian
Cletus the Slack-Jawed Yokel
Colonel Klink/Homer’s guardian angel
Colonel Leslie “Hap” Hapablap
Comic Book Guy
Comptroller Atkins
Cookie Kwan
Corporal Punishment
David St. Hubbins
Nigel Tufnel
Derek Smalls
Devil, The
Bumblebee Man
Disco Stu.
Doctor Marvin Monroe
Doctor Nick
Dr Colossus
Dr. Julius Hibbert
Duffman
Elderly Jewish man
English guy Homer pulls out of his sugar pile, The
Frank Grimes
Frank Grimes’ son
Freddy Quimby
Gerald/The kid with one eyebrow
Gil
Groundskeeper Shamus
Groundskeeper Willy
Guy Incognito.
Handsome Pete
Hank Hill
Hank Scorpio
Hans Moleman
Helen Lovejoy
Homer Simpson.
Homer’s little-seen half-brother Herb.
Horatio McAllistar (a.k.a. The Sea Captain)
Inanimate carbon rod
Itchy
Jacques
Jasper
Jebidiah Springfield
Jesus
Jimbo Jones
Jimmy, the kid who thought he could live without zinc
Joey Jo-Jo Junior Shabadoo
Johnny Carson
Johnny Tightlips
Jub jub
Judge Harm
Kang
Kirk Van Houten
Kodos
Lard Lad
Laslo Panaflex
Legs
Lenny Leonard
Leon Kompowsky (aka Michael Jackson)
Leonard Nimoy
Leopold
Lieutenant L.T. Smash
Lindsay Nagle
Lionel Hutz
Lisa Simpson
Little Timmy
Lucille Botzcowski
Lucy Lawless
Lugash
Lunch Lady Doris
Lurleen Lumpkin
Lyle Lanley
Maggie Simpson
Mandy
Marge Bouvier Simpson
Martin Prince
Michael Jackson
Milhouse from Shelbyville
Moe Syzlak
Mr. Largo
Ms. No-Means-No
Nahasapeemapetilon octuplet who was dressed as the Red Baron, The
Ned Flanders
Nelson Muntz?
Otto
Patty Bouvier
Paul Lynde
Paul McCartney
Pinchy
Poochie
Principal Skinner
Prof. Frink
Rabbi Krustofski.
Bleeding Gums Murphy
Radioactive Man!
Rainier Wolfcastle
Ralph Wiggum
Real Seymour Skinner, The
Reverend Lovejoy
Rex Banner
Ringo Starr
Robotic Richard Simmons
Rod Flanders
Roscoe
Santa’s Little Helper
Scratchy
Selma
Serak
Sideshow Bob
Sideshow Luke Perry
Sideshow Mel
Sideshow Rahim
Smithers
Smithers Snr.
Snowball II
Sophie
Sophie’s mother/Cokie Roberts
Spongebob Square Pants
Squeaky-Voiced Teen
Stampy
Steven Hawking
Sting
Stonecutter # 1
Superdude
Superintendent Chalmers
Surly
Teller
Tibor
Tod Flanders
Troy McClure
Uter
Very Tall Guy
We’re missing a few obvious ones, people.
God
I forgot her name but how about Lisa’s tap dance teacher.
“Tappa-tappa-tappa.”
Maud Flanders
President and Mrs Bush Sr. That was a great dennis the menace parody.
Wow! Life sure is full of interesting coincidences. Just last night they showed that very episode on my local Fox affiliate, WUHF-TV. (Channel 31, Cable 7 in Rochester, NY; The UHF part is no doubt a generic reference to Ultra High Frequency, a somewhat odd choice. WXXI-TV, our PBS affiliate is also an “Ultra” and has a near-ten year seniority, going back to circa '71. Would you be surprised over the Channel number being… 21? At last its a specific reference. And, so far, I haven’t heard of any Very High Frequency station having the call letter WVHF!)
I am certain that it was the 11 pm time-slot, although IIRC they still have both 5 pm and 6 pm slots for the Simpson clan as well.
“Shelbyville” has a familiar ring to it, including the neighboring town and rivaling kid characters, so I have no doubt spotted it once before, probably also in syndication, rather than network original or network rerun.
But I did not clearly recall the second Milhouse, so my memory isn’t all that perfect thse days, assuming that I was paying full attention the first time around.
TBJ
Edna Krabappel
Kent Brockman!
“Thanks to you, Mayor Simpson, we’re all taking golden showers!”
We’ve got Rabbi Krustofski, but no one’s mentioned Krusty the Clown (Hershel Krustofski)? Hey HEY!
I’d like to do a second one, but I’m afraid I might have missed his name in someone else’s post. Just to be safe, could someone search the boards for a Hugh Jass?
That’d be Little Vicki [“I’m just Vicki now.” “That’s Little Vicki.”] Valentine.
That’d be Little Vicki [“I’m just Vicki now.” “That’s Little Vicki.”] Valentine.
How about Marge’s mother, Mrs. Bouvier? I don’t know her first name.
Homer’s mother?
President George Bush senior
Janey (Lisa’s friend)
Sherri and Terri
Dr. Hibbert and Hibbert’s wife and kids
Chief Wiggum’s wife, Sarah
Nelson’s father and mother
Snake
The one armed guy who runs the war collectible shop with the cigarette in his mouth
Dancin’ Pete (the little guy who looks like Krusty who dances)
Wendell (boy in Bart’s class who looks pale)
Lisa’s teacher (Ralph said she got Lyme disease)
Louis (kid in Bart’s class)
Sanjay (Apu’s friend)
Manjula (Apu’s wife)
Marge’s father (the flight attendant)
Marge’s psychiatrist (the one she will remember by Lowenstein)
Bart’s twin, Hugo
Mrs. Glick (the old lady Bart pulls weeds for and gets ribbon candy)
Agnes Skinner
The lady that runs the whorehouse and Bart has to work for her when he knocks the gargoyle off her roof
Steve Guttenburg
Bob Dole and Bill Clinton
Homer’s exact double (Guy Incognito?)
Paul McCartney and Linda McCartney
Jasper (freezer geezer)
The crazy cat lady who throws cats at people
Herman
Jacqueline, of course. I’m sure some of the people on your list are new, but there was a rule about two characters per poster. 
I figure since everyone went over 100 characters I can add the remaining ones.
Ruth Powers
The Yesssss! man
Pyro and Gyro
The lady Moe was dating who dumped him before they went to Hawaii
Greta Wolfcastle
Old man who drops his pants for food?
Dolph, Kearney, Jimbo
Rich Texan
That gay guy who ran the novelty shop in the mall who saved Bart from the reindeer and who said “annual gift man”
Ruth Powers’ daughter, Laura
Menthol Moose
Mel Gibson
Gina, the girl in the prison next door who befriends Bart
Barney’s uncle who ran the bowling alley
Funzo
Gary Coleman
The guard at the Try N’ Save when bart stole Bonestorm
Scott Christian