Reims - champagne tours ?

I did an overnight, so I had the better part of 2 days there. I took back-to-back tours at Tattinger and Martel on the first day (it's a short walk between them), then the Mercer tour in Epernay on the second day. I enjoyed them all. Mercer was the most fun and the wine I liked best (they put the least Chardonnay in theirs). Tattinger was stingy with the tasting, but to be fair, they pour from their best. Martel was the most generous. Each tour was different because the caves are different and the family/winery history is different. There's a little repetition about the méthode champenoise but not much. Be sure to take something warm to wear, the temps in the caves are pretty chilly and a little damp. There's a small TI at the train station and a larger one on the side of the cathedral. They will help you book tours if you haven't done it in advance. Some are walkups (like Mercer) and you may be in a line for a bit, others need to be booked in advance, some are possible to book on the day.

I liked the basilica (near Martel/Tattinger) at least as much as the cathedral. The WWII Musée de la Reddition (where the nazi capitulation was signed) was very interesting too.

I was just there for 3 days and I second Chani's comments, including the other sites. I liked the information in the Taittinger tour and you see quite a bit of their caves, the Martel tour spends less time in the cellar and I liked their tasting much better - personable and a good sampling. Both are not too far from the center of Reims and are just blocks apart.

Mumm's is easiest to reach without a car, just take the high speed train from Paris to Reims, 45 minutes, and then you can walk to the cave. Miles of caves, they take you on a tour of a short segment, and you get some tastes. This is not Mumm's Napa.
Many of the other houses require you have a car or tour.

Such good information. Thank you everyone !