Any lossless format will be equally good. FLAC are non-proprietary, while some other lossless formats tend to be specific to either Microsoft or Apple applications. However, they tend to be widely supported within MS or Apple formats, while FLAC, at this time, isn't always supported by one's application of choice (or requires a third-party add-on, etc.) Also, high bitrate MP3s are pretty darn good, and will be indistinguishable from lossless in most cases (but yeah, 128kbps is pretty bad. Definitely upgrade from that), so if you don't have a lossless option for something, it's not the end of the world.