You never forget your first trip into a Costco (NASDAQ:COST). The bare decor. The bulk packaging. The great deals.

Warehouse clubs are retail at its best. Sure, discounters such as Target (NYSE:TGT) are ramping up their grocery offerings. And grocers such as Safeway (NYSE:SWY) and Kroger (NYSE:KR) are dedicating more shelf space to bulk-sized values. Heck, even Amazon.com (NASDAQ:AMZN) is shipping sundry goods in bulk, and it does so for free to its Amazon Prime members.

Costco's still got it going on, though. The question is whether it's doing well enough to justify its current valuation. Not all Fools agree. Anders Bylund is bullish on the company. Larry Rothman is bearish on the warehouse-club bellwether.

Where do you stand when it comes to Costco? That's what this week's bout is all about.

Duel on!