My son is using Critical Thinking I with a group this year.  It's a group of 6th-9th grade boys. 

Logic of any kind can be dry, IMHO.  The Bluedorn books are at least a little lively.  The Critical Thinking books have some fun examples but basically it's going through different types of arguments using logic, so I find it dry.  Good for the brain, I suppose.  I didn't like Logic in college, so that's where I'm coming from.

I think CT is very similar to a Christian logic book I have that I can't think of the name right now -- maybe it was Traditional Logic.  CT has a little more, though.

I've also heard about Introductory Logic and Art of Argument and more.  If you go somewhere like ChristianBook and search for "logic," you'll see quite a few options.  Maybe some will have sample pages?

Julie

We used the CT workbooks when the kids were elementary-aged. They were okay, but very repetitive, which bored my kids after awhile. In the middle school years we switched to The Fallacy Detective, which both my boys liked a lot.  They "got" it, but don't remember what any of the fallacies are called any more.  However, they can usually spot a fallacy when they see it.

Our co-op offers a formal Logic class for 9th-12th grades.  I've debated about whether or not to send my older son (now in 10th grade).  His reading comprehension is something we're still working on, and that logic class has a TON of reading.  However, he's learned that the class includes The Screwtape Letters, and wants to read it for fun, so I think we're going to play it by ear and see how it goes.  One big problem is that the class is 6th period; end of the day when he's beat.  He's also the custodian at our co-op and works 6th period.

I'm thinking that if we choose the formal class I'll wait until 11th or 12th grade for him.

If you're interested, our co-op has the Logic class on-line: http://youth.biola.edu/academics/torrey/schedulesfees/  Click on the Fall 2010 schedule under on-line classes.  I highly recommend this co-op -- it's through Biola University, a Christian university. They have the STAR program for Jr/Sr high school students and Torrey Academy for advanced students.