The Summer Foundation Dilemma.. Help!

I am on the hunt for a perfect summer foundation, and I need your help! It's been a year since I started using liquid foundation, and the only ones I've bought were the Revlon Colourstay, Barbara Daly Oil Free Foundation and Rimmel Lasting Finish Foundation. I don't want to repurchase any of these, and am on a look out for my first high-end foundation :) Here are the contesters:

1. Dior Diorskin Nude Foundation (£29.50)

I'm currently using a sample that I got at House of Fraser, and I have to say I'm not totally blown away. The coverage is pretty light - not as light as a tinted moisturizer, but to the extent where I'm not sure if it defeats the purpose of wearing a foundation. The finish however is incredibly natural, even with the MAC MSFN on top. I want to love this foundation, but I also feel I get oilier a bit faster? It doesn't help that I'm out of my Liz Earle Cleanse & Polish that usually controls my oils and blemishes. I have quite a lot of the sample left, so I will keep testing.

2. Chanel Vitalumiere Aqua (£31)

I tried the tiny samples that come in magazines for this and the application was a dream - it felt like a liquid mousse. That being said, it didn't really look that natural - it was quite matte. The coverage however, was perfect. But it was also 'unsettable' with my MAC MSFN, as it looked quite cakey when I did. The price also is one of the higher ones, considering you get a plastic packaging..

3. MAC Face & Body Foundation (£23.50)

I've just heard so many good things about this, and the major plus is that it's the cheapest of them all, and you get four times as much as the other foundations. That being said, I'm not sure I'm a fan of the wetness that you apparently get, and also I worry about it breaking me out as MAC foundations seem to do that to a lot of people.

Some others I've been contemplating:
- Guerlain Lingerie de Peau
- Bobbi Brown Skin Foundation
- MaxFactor Second Skin
- Bourjois Sleep Effect or Healthy Mix

I think you can tell that I'm looking for a light-medium coverage, mostly water-based, light-weight foundation that claims to be a 'second skin', or that you aren't wearing make-up and all that good stuff. If you have any suggestions at all, please let me know, and link me to your reviews if you have any of these or of any summer foundations you love! :)

So girlies, what is your favourite foundation for the summer? :)

<3yu