Leon to Guanajuato

What is the best way to get from Leon airport to Guanajuato City? I am assuming it's either bus or taxi.
Any advice appreciated.

There are no buses from the airport. The easiest way is by taxi straight to Guanajuato. This will cost you about $350 pesos. Your other option (much slower, but cheaper), would be to take a taxi to Silao (about $100) and then take a bus to Guanajuato.

What is the approximate cost of the bus fare between Silao and Guanajuato? There will be two of us, so I am wondering if it will just be easier/cheaper to take a taxi.
Thanks!

For 2 people, I think it would be quite silly to do anything other than taxi. The bus between Silao and Guanajuato is cheap, but would take you A LOT longer.