I don't much like Head Games; It's a cute Princess Bridesque "So I can clearly not choose the wine in front of me" scenario, but you're essentially paying mana for something that's just as likely to hurt you as help you. Meh.
General's Tent is thematically similar in that it creates a mind games scenario, but it's a more interesting one. Once you've got a fully armed General's Tent, can they really afford to send all their troops at you, knowing you might have Trap waiting? Can they really afford not to attack knowing you might be able to alpha-strike them with an assassination? Invasion seems like the least interesting from a "surprise!" perspective, but this is an artifact creating more artifacts and that spells "Put me in a dwarf deck for fun and profit". It's a little slow and spendy (9 mana over 3 turns), but it might be a fun thing to put in a longer term control deck.