Of American-English origin, the phrase to look, or to feel, (like) a million dollars, or (like) a million bucks, means to look, or to feel, extremely good, or extremely attractive.

The earliest instance that I have found is from the account of a baseball game between Buffalo and Newark, published in the Buffalo Evening News (Buffalo, New York) of Thursday 18^th September 1902:

Two fierce batting rallies won two games for the Bisons at Olympic Park yesterday. Besides that, both Magee and Amole outclassed their opposite twirlers. Magee was quick as lightning, and Amole served up a line of southpaw dope that the Skeeters flew away from as if it were pennyroyal.
At that the Burn’emites looked like a million dollars for the first six innings of the first game. Then the Bisons shaved off a whole lot of hits from Mr. Moriarty’s delivery and scored four, whereupon the Skeeters retired to the swamp. They got in the first bite at that, in the first inning, but after that the game was a blank to them.

The second-earliest instance that I have found is from the same newspaper, the Buffalo Evening News, of Friday 26^th June 1903:

Kinney’s Windsor Club.

The Hon. James E. Kinney, boxing promoter, who has the new club at Windsor, Ont., blew into town this morning looking like a million dollars. Kinney is on his way to Boston, where he hopes to match Young Corbett and Dave Sullivan for his clubhouse on July 20. Otto Sieloff and Matty Matthews will do battle before J. Kinney’s club July 3.

The phrase has sometimes been used in contrast to like thirty, or 30, cents, which means cheap, worthless, as in the following paragraph from the Wilkes-Barre Record (Wilkes-Barre, Pennsylvania) of Friday 13^th June 1913:

“Bucky” Friel looked a million dollars the first two innings, and like 30 cents at the close of the third.

The phrase like thirty cents dates from the late 19^th century; for instance, the following is an advertisement for Parker, Bridget & Co., published in The Times (Washington, D.C.) of Monday 30^th August 1897:

They’re “Rattled.”

It makes the other clothiers feel like “thirty cents” to see us selling these splendid quality odd pants from $12 to $20 suits at $1.90—for they can’t begin to meet such a price for good pants. It’s a bully good chance for you men to save money.
Odd Serge Coats and Vests going at $4—worth double.
Money back if you want it.