BJCP 6A
An elegant, malty German amber lager with a clean, rich, toasty and bready malt flavor, restrained bitterness, and a dry finish that encourages another drink. The overall malt impression is soft, elegant, and complex, with a rich aftertaste that is never cloying or heavy.
Modern domestic German Oktoberfest versions are golden - see the Festbier style for this version. Export German versions (to the United States, at least) are typically orange-amber in color, have a distinctive toasty malt character, and are most often labeled Oktoberfest. American craft versions of Oktoberfest are generally based on this style, and most Americans will recognize this beer as Oktoberfest. Historic versions of the beer tended to be darker, towards the brown color range, but there have been many 'shades' of Märzen (when the name is used as a strength); this style description specifically refers to the stronger amber lager version. The modern Festbier can be thought of as a pale Märzen by these terms.
Buergerliches Ur-Saalfelder, Hacker-Pschorr Original Oktoberfest, Paulaner Oktoberfest, Weltenburg Kloster Anno 1050