5DIII and 7D. I switched from a D700 and D300 last year, for a variety of reasons.
There are times when I wish I'd passed on the MkIII and just kept the D700 as my full-frame body but there was really only one lens I used on it, the 50/1.4G (excellent). I am not disappointed with the 5DIII, it's more a matter of sentimentality (I went through a lot with that D700) and secondarily the cost of switching (I lost a lot on the D700, thank goodness I bought it after it'd been out for a while...)
Despite iffy image quality under some circumstances the 7D + 15-85IS is a great all-round replacement for the D300. It shoots 14-bit files at 8fps without a grip, has a bigger buffer, etc., all of which is extremely handy for shooting rockets in flight. This was what started the brand switch, as I primarily bought it for this, coupled with the 135/2 L, a lens for which there is no real equivalent in the Nikon range, the 135/2 DC having a very different rendering from what I was looking for.