Interesting, the canonical examples have been removed from the Wikipedia TTIP article.
The first example is Vattenfall vs. Germany. The former, an energy provider, sued and won against the latter, for the decision to phase out nuclear energy.
The second is Philip Morris vs. Australia, because of the decision to require plain packaging on tobacco products.
I can't certainly argue against an agreement made against two parties, but the problem here is that TTIP is made in secret, between arguably corrupted representatives of populations which wouldn't certainly agree with such decisions.
(1)=I've rephrased this from http://blogg.uio.no/jus/smr/multirights/content/the-ttip-inv...
Vattenfall suing the German state makes sense considering the business impact the change had. Add to that, Vattenfall is wholly owned by the Swedish state so the TTIP should have no impact what so ever on their dealings.