I have to admit that I like them all, but sometimes one way works better than the others depending on the group. At times I have come fully prepared to challenge the group with something I might be excited about only to bag the whole plan because real people deal with real life and needed something other than my plans for the evening. As a leader you have to pay attention and listen to your group to determine what is going to work best. If your group doesn't have time to read and do homework, you may want to take a different approach and prepare so that all they have to do is show up.
We started a sermon series at Vineyard Community Church this week that plays into the small group studies. We are reading through the book of Acts and there are some guided questions that will be made available to us each week. I really like this because it gives the leader a chance to just participate with everyone else and the main teaching can come from church on Sunday.
I am sure by the time this series is over, I will be ready to jump into a book or something different and lead some more. It is nice to get a little break, but not have to take a break from the group.
Not sure if there are a lot of readers to this blog yet, but if you do, please comment and let me know what resources you like to use for small group.