I love the Liar Lunatic or Lord argument, but it's pretty silly.
If you don't know this famous argument (first made by CS Lewis, I believe), here's a short summary: You say Jesus was a good man, but you don't believe he was God. Fine. You're either calling him a LIAR (He was dishonest about who he said he was) or a LUNATIC (He falsely believed that he was God). Either way, you're stuck with the problem of explaining how a Good Teacher whose ideals we should follow could be compatible with a person who wasn't honest with us about his person-hood or was mentally unstable.
This is a pretty good argument at first glance. I'll admit that I was smitten with it for quite a while.
But the problem is that the Liar, Lunatic, or Lord Argument is that in essence it's claiming that a Liar can NEVER tell the truth and that a Lunatic can NEVER say something sane or worth repeating. I think you'd find us hard pressed to make that sort of leap. Liars are usually proficient at telling truth-telling; just think of all the politicians who lie through their teeth to get elected and sometimes end up passing legislation that's worthwhile. And Lunatics are sometimes better at seeing reality than the rest of us- they are often simply missing the filter that allows them to interact with the rest of us in a reasonable, rational manner.
Now, this isn't to say that Jesus wasn't Lord. I believe He is. I just don't like this particular argument because it oversimplifies matters where there isn't a simple answer.