Lindeman's is...OK...but you have to understand that they sweeten their lambic. As do Boon, Liefman's, and most of the others. To really taste lambic in all its greatness, get a Cantillon. They are the best lambics widely available.
Other Belgian favorites:
Rodenbach Grand Cru - it is a CRIME this brewery was shut down. One of the best beers the world has ever known.
Hoegaarden Wit - Wit is one of my favorite styles of beer. It's incredibly complex, light, clean, Celis Wit, which used to be made in Texas (are they back??) was better. The same guy, Pierre Celis, started Hoegaarden before starting Celis in Texas. Great White by Lost Coast in Eureka California is another Wit made domestically.
Hansen's lambic - more raw than Cantillon, but a great lambic for those who love the horse blanket
There are other rare, authentic lambics around, too. Keep your eyes peeled. There was a great Belgian bar I found in Philadelphia that had a ton of beers, including authentic SOUR lambics I had never tasted.
Chimay/Orval/trappists in general - try em all. Monks who make beer. It's a higher calling
Duchess de Bourgnoune - I throw this one in because I had it at the Toronado in San Francisco a while back (side note...if you love beer and are in San Francisco GO TO TORONADO ON HAIGHT STREET
). Anyway. What a beer! Dark, malty, with a tart hint of sour lambicy flavor. Fruity sweetness. Complex, weird, unique, Belgian. It reminded me of a Rodenbach. Best beer suprise I have had in years. Anyone know anything about this one?
Cantillon, Cantillon, Cantillon - probably the best beer made in the world today. Go there if you are ever in Brussels. Buy it if you ever see it. I have a bad feeling they won't be around forever. All Cantillon lambics are world class, authentic representations of the style.
And so many many many more. There are bars in Belgium with literally thousands of beers available. Seasonals, small breweries, beers that never see anyplace outside of Belgium. Try to go there someday. I thought I would never be able to leave Bruges.