If there was only 1 blue deck to fight the current metagame and perhaps to fight the future metagame (by changing the SB), which one would you choose to play and why? Would it be a Countertop build, Next Level Threshold, Team America, UGW Tempo, Bant Aggro, High Tide or something different?

I know there isn't a perfect deck in legacy, but at least consistency is very important when it comes to a properly build, strong legacy deck.

I know of some blue players that constantly switch between decks instead of holding on to one deck. Why is that? Is it because blue lacks consistency in general? I don't know of many Goblin players that want to play something different... Goblins is just a very consistent deck that always does great in legacy and always have done great before. It's what it is. Now just tell me about a blue deck that is just as good as Goblins in terms of strategy, consistency and power level. Countertop immediately came into my mind, but even this deck doesn't seem to be the right call in todays meta, which I think is kind of a shame and a joke at the same time. Countertop to me is still one of the biggest reasons to play blue. When I think about blue, I think about Countertop and not about a tempo variant that suffers without the long term card advantage that Counterbalance and Sensei's Divining Top offer to the deck.

So, my personal vote goes to a Countertop build with Trinket Mage, EE, Needle involved to fight tribal, next to a red splash for Firespout, Pyroblast, Red Elemental Blast, Ancient Grudge.