Onderzeeboot
Ecstatic Orb
I find myself in complete agreement with ahadabans on this issue. Why should one of them stand out particularly? Any one of those "will do", and yes, they do leave room for a Terminate to solve the question they pose. Is that a bad thing? If your control deck can't handle a single removal deck, because you only play a single threat, then try building a better control deck with more finishers. From my p.o.v. it's good that they can be answered, because otherwise you'll get BS cards like Grave Titan or Deadship Navigator, which just completely wreck a game.Now, synergy with other cards and archetypes in your cube is another matter entirely; but for plain ol' control decks just looking for value and board stability, none of the options presented stand out particularly in one way or another.
Also, has anyone actually tried Kothophed? I saw it in one game on Day9's channel, where it completely warped the match by drawing a bazillion cards. That trigger is the real deal!