I have terrible dark circles under my eyes and have tried most things over the years.
I actually do rate the collection 2000 one especially for the price.
It is so hard to get coverage without getting cakes. I didn't like boi-ing. Erase Paste, also by benefit, is quite good but it is thick and so can look heavy. I do quite like the Estée Lauder double wear one, it is a creamy one with a wand. I tend to prefer wand ones as I find the pot ones quite heavy and cakey to apply.
I did buy the phwoar stuff after seeing it on here. It's ok, pretty similar to boi-ing but I do tend to go for the collection one over it. In fact I have most of the above at the mo and always reach for the collection one, probably because it is the best match for my skin colour.
I do think application is key. I tend to rush it on with my finger (one year old and three year generally hanging off me or 'helping' me apply my makeup!) but when I occasionally use a brush it is better.
There is a you tube video showing how to apply it in a triangle shape under your eye, ie don't just cover the dark bit but a large area underneath and blend it all in. But helpfully I have no idea who the make up artist was, sorry!
I don't rate any of the touché eclat things, have tried that, the By Terry one, cheap ones and none of them work if you have seriously bruised looking rings. I think they just highlight the problem. Possibly ok on top of the concealer.
Virtually nothing shifts my circles apart from a suntan! They say water and sleep but I don't think it makes any difference.