Kasumi, but Samara gets credit for somehow surviving on the playthrough where I tried to get my entire team killed, and therefore saving Shepard.
Also most bioware games seem to have that one character you really hate or just find boring compared to the others. I hated Jacob, Kaiden was dull and I killed him every time. In DA it was Alistair but I still had him in my party all the time cos he was the only person with high enough strength to wear the grey warden armor and I ended up liking him by the end, and Carth is good if your light side but his constant 'stop being evil' whinges are annoying if your dark side.