Yes, if it has a large selection of music I enjoy (Japanese, Korean, Chinese, and non-english music) and it is fairly price at 2-5 dollars a month, and allows me to download the song for offline playing or if there is a hack to download music from the streaming server.
But, the quality of the music on YouTube can sometimes be not as good as High Bitrate MP3 like 192-320 KBps, and songs get taken down after the RIAA or copyright holder files a copyright complaint. The ads are also annoying on YouTube compared to a legal music download and streaming site which always have the songs which are high quality and never get taken down.