For the last five years or so I have primarily used the New King James Version for preaching, as I find it the closest to the KJV, usually just clarifying all of the "Thou arts" and such, yet keeps the general flow of the KJV. When doing sermon prep, I have 16 different translations I can compare, and have found a few that are quite good, depending on what you're looking for and/or need. My method is to compare each to the KJV, especially certain Scriptures, to make sure that the translation doesn't stray too far away from the meaning (using the original Hebrew and Greek is a big help as well, which can be easily accessed using Strong's Greek and Hebrew Numbered Concordance). Here are a few:
--International Childrens Bible (ICB) translates in a very clear and easy-to-understand format, suitable not just for children, but for anyone.
--The Message (MSG) does put it in today's language, but is a bit harder to follow along with other translations in a sermon-style setting. I think it's a good practical study Bible in and of itself, though, for the "regular Joe," or especially for those who have had limited or no exposure to Christ.
--New American Standard Bible (NASB) and the New Revised Standard Version (NRSV) are, for the most part, pretty decent as well, and I would recommend them to those really wanting to study the Bible (almost any translation with study helps is a good choice).
I'm not one of those "If the KJV was good enough for Jesus, it's good enough for me" guys, especially since Jesus didn't speak English. But I understand that the KJV is sometimes very difficult for the modern person to grasp; I've even had some say that the Bible wasn't interesting, because they had a hard time reading Shakespearian English. As for me, though, growing up with the KJV, I find the NKJV to be the best choice, and when clarification is needed, I consult various other translations, and have used verses from all the above versions in sermons at one time or another.