I fell sorry for Mr Fizzy Vimto nails. I watch many nail art videos and read mayn blogs, and get super excited when I saw awesome swatches...I assume he never listens....
Until my birthday came along, and I opened the wonder that was GOSH holo! :D It's sold out in the UK so I have NO diea how much he paid for it on ebay, but it was such a lovely surprise as it was the last thing I'd expected him to get me :D
If you haven't read any reviews on the GOSH holo, then it's bascially a one night polish, made for a night out to make your nails wonderous and magical, so it chips and peels really easily. Putting a top coat on dampens the holo, so that's not recommended. However, it is pretty easy to paint over any chips or peels as the new polish blends in really easily with the old polish, and it's really hard to see the join.
It's pretty hard to get a decent shot of a holo (especially with my Blackberry camera -__- ) as you need a video of it shimmering in the sun, but this photo shows the rainbow pretty well :)
I've not tried any other holos as only the more expensive brands tend to do them (and in different colours also), but a holo seems to be something to have at least one of in your collection!