Pastel nails are perfect for Spring. They are like a breath of fresh air to the darker colours of winter and the pinks and reds that are very much the norm. Don't get me wrong I still love the classic and non offensive nail colour but something different is exciting to try out.
The 3 pastel colours I love at the moment are, in no particular order, Bikini Blue by Jessica, Barry M's Pale Purple and Mint Candy Apple by Essie. Gorgeous colours and I always have compliments when I wear them. The quality for these are decent. They can be a little streaky (like any other milky light colours) so at least 2 coats are required. I would suggest layering these with the thinest possible layers each time to make it as even as possible. But honestly it is not that much of a problem. I find that by using a super glossy top coat you can get away with many minor flaws.
A few things I would say about pastel nails... I personally find that shorter nails are more flattering for these colours. You also need close to perfect cuticles. As the colours are generally quite bright this tends to draw attention to your nails and the state of your cuticles!