Bible Version?

I'm planning to read the entire Bible from start to finish. So far I'm nearly finished with Genesis and have been using the KJV. This is because many evangelicals and fundamentalists I've spoken with believe that it's the only true Bible and all other versions are corrupt. The problem is is that I'm not very familiar with old English. I've experienced some difficulties while reading, such as having to look up many words in the dictionary, and having to go to another Bible version to fully comprehend the meaning of certain verses. Sometimes I feel that I'm not fully absorbing the real meanings. What other versions are there with a good translation and a more modern and understandable language? I've heard some awful things about the NIV.