I find Japanese beers tend to taste fairly similar. They're almost all quite pleasant, but not that distinctive -- medium-low alcohol (4.5% to 5%), high-carbonation, mild lagers. Sapporo is my favorite of the big three, then Asahi, then Kirin. The Japanese supermarket near my house regularly has ridiculously cheap sales on these, so I drink a fair amount of them.

I also like Orion, which is the only Japanese beer I've seen sold where I live (West Coast, USA) that's actually brewed in Japan (Okinawa, specifically) and imported to the U.S. It's quite weak (ABV 4.7%), but has a distinctive flavor, and comes in large bottles.

Asahi, Sapporo, and Kirin as sold in N. America are all brewed in the U.S. and Canada by Molson and Anheuser Busch (under license from the 'real' breweries, and according to their recipes, of course).