When I'm AT Oktoberfest - Paulaner
In the states - I agree with the previous suggestion of Tyranena Oktoberfest (2007 vintage) from Lake Mills, WI. Why do I mention vintage? Last year's Oktoberfest had an AWFUL "bouquet". I kid you not, it smelled like vomit, but tasted very good - kind of hard to seperate the taste from the smell in the overall experience however. Overall, Tyranena rocks. It is one of the best breweries I've been to out of several hundred I've visited. The owner/brewer Rob specializes in HUGE pales, IPAs, and a lot of bourbon barrell aged browns, stouts, and porters.
It is also quite convenient that I live 10 miles from the brewery.^
If anyone on here is ever in the MSN area, it is well worth a visit to Tyranena. And if anyone needs advice for good brewpubs/beers in WI, feel free to PM me.
Also, I was in Pittsburgh a few years ago on business and Penn Brewing had their Oktoberfest celebration going on at the time. Their Oktoberfest and Hefeweizen are outstanding!!