The best is the first
We can leave our mana up, if we need to counter something we use Mana Tithe, but if we don't get a chance to use the counter we can use our mana to cast one of our instant-speed token producers
Choose what suits your style and needs
With a penchant for direct damage spell-slinging, Imodane is a 4/4 legendary creature for two colourless and two Red mana that reads: Whenever an instant or sorcery spell you control that targets only a single creature deals damage to that creature, Imodane deals that much damage to each opponent. Due to a tricksy rules interaction with how Imodanes damage is dished out, its actually far more busted than you might think
Maze's End, I think, is a no-brainer
When you cant play four Counterspells, you need to diversify with cards like It'll Quench Ya!, Sokka's Haiku, or Disallow