Nathan Lane as Oscar?

there is no way nathan could be Felix
Yes he could play it but nobody would believe it.
Especially after Max Bialystock.
I mean nathan is loud, obnoxius, kinda messy and hilarious as hell and that's the perfect Oscar.
And besides Matthew Broderick could never play a believeable Oscar he'd have to be Felix opposite Nathan's Oscar

So I'm not the only one after all. Seriously, I always saw Nathan Lane as being the funnier Felix, and Matthew Broderick as the superior Oscar. But nooooo...they couldn't possibly play anything but their Producers-style characters.

Typecasting sucks.

The Odd Couple premiered on Broadway in 1965. The original the cast starred Walter Matthau as Oscar Madison and Art Carney as Felix Ungar. Matthau was replaced with Jack Klugman and later Pat Hingle. Carney was replaced with Eddie Bracken and later Paul Dooley.

In 1970 the McMaster Shakespearean Players performed The Odd Couple with Martin Short as Felix, Eugene Levy as Oscar, and Dave Thomas as Murray before any of these performers were famous.

In 1994 a version of the play moved to Glasgow and toured Scotland starring Gerard Kelly as Felix, Craig Ferguson as Oscar and Kate Anthony as Gwendolyn Pidgeon. Kelly reprised the role of Felix at the 2002 Edinburgh Fringe, opposite Andy Gray.

In 1996 Klugman and Tony Randall reprised their roles from the TV series for a three-month run in London. Klugman had previously played Oscar in London opposite Victor Spinetti as Felix.

In a 1997 issue of Premiere Magazine, Billy Crystal and Robin Williams announced a possible stage revival in anticipation of success of their film Fathers' Day. When that film failed at the box office the Crystal/Williams revival was quickly forgotten.

In 2002, Simon wrote an updated version of The Odd Couple, titled Oscar and Felix: A New Look at the Odd Couple. This version incorporated updated references and elements into the original storyline. This production ran at the Geffen Playhouse in Los Angeles from June 2002 to July 21, 2002 with a cast that starred Gregory Jbara (Vinnie ), John Larroquette (Oscar), Joe Regalbuto (Felix) and Maria Conchita Alonso (Ynes).