I have the 32GB version which I find is ample. I think i'd have been a little pushed with the 16GB due to wanting to take multiple videos with me on longer trips. Although, i'd probably have just increased the compression to save space. Music and photos don't really take up that much room unless you're importing raw/lossless or have a huge music library (be selective
with the exception of the odd game weighing in at 1GB each, my space is only pushed when I put quite a few videos on it.
If money is really tight, 16GB is fine, but if you can stretch for the 32GB I think it's worth it. 64GB seemed overly expensive for just the extra 32GB. When making my choice I thought i'd just about manage with 16GB so bought the 32 to leave a bit of growing room
