Tasting blind

If you've never done so, a blind tasting is a fun, easy way to try out a bunch of wines and not get overly-influenced by the marketing or over-awed by the label.  Take your wines, put them into brown bags -- ask at the wine store for some extras if you need, they should be glad to give you some -- and completely remove the foil and pop the cork.

Have someone else label the wines, ABCD etc, in no particular order.  You do these two things (removing the foils and having someone else label the wines) in order to keep yourself from associating a particular bag (or particular foil neck) with a particular wine; trust me, the first couple times you do a blind tasting, you'll be hunting for clues as to what it is you're tasting.

Taste wine A.  Make some notes.  Rate it.  Chew it over a bit.  Repeat with B, and so on, until you're done.  Share your notes with other people tasting the wines; compare and contrast ("Oh, so I'm not the only one who thought that wine A smelled like maple-cured bacon!")

And... reveal.  Sometimes, it's a complete surprise (once, at a blind tasting, my dead-on favorite, and the hit of the night was a $14 cabernet; everything else was $20 and from Big Name Regions).  Sometimes, not.  But, it's always fun.

Even better -- make a party of it.  Have everyone bring a bottle in a bag (and don't worry about repeats; sometimes, it'll keep you honest!), and you, as the host, do the foil and cork removal.  Just specify a grape type or region ("this weekend, we'll be tasting merlot," or "Let's find wines from Rioja," would work as a theme), and a price point (to keep it fair on all attendees, and to eliminate the fear of "what if we're the only ones bringing a $10, unusually-named Argentine wine?").  Let your guests discover each other's wines... and perhaps you should be the one throwing a ringer into the mix.