#2 Max Verstappen
Here's a controversial one, but let me explain.
Max Verstappen made a number of mistakes during 2018, that's undeniable, but the Dutchman was probably the best driver of the season after the return from the summer break.
Verstappen strolled to a win in Mexico, completed several superb comeback drives from engine penalties (most notably in the US) and would've won in Brazil, had it not been for a complete brain-fade against Esteban Ocon.
Does he need to work on his race-craft? Yes. Has he got a lot to learn before becoming a world champion? Yes. But that will come with time, and at 21 years of age, he certainly has plenty of that on his hands.
Verstappen has a level of speed that very few drivers possess, and he showed it to devastating effect in 2018.
Despite numerous engine penalties and mechanical failures, he finished ahead of Valtteri Bottas in the overall standings and only just classified behind third-placed Kimi Raikkonen.
If Red Bull provides Max with a car that's on par with the Mercedes and Ferrari, don't rule out there being a new world champion this time next year.
Some might say that putting Verstappen ahead of Alonso is unfair, especially when the former's mistakes are considered and that's a fair point.
However, with how unlucky Max has been and how big of a margin he out-performed a driver of Ricciardo's quality by, I give this one to the Dutchman, although it is very close.