Which of the following inhalational agents has the minimum blood gas solubility coefficient ?
Desflurane has minimum blood : gas partition coefficient (minimum blood solubility) → fastest onset and recovery amongst inhalational anaesthetic agents.
Speed of onset & recovery in decreasing order (Increasing order of B : G partition coefficient & blood solubility) :-

Desflurane (0.42) > cyclopropane (0.44) > N2O (0.47) > Sevoflurane (0.69) > Isoflurane (1.38) > Enflurane (1.8) > Halothane (2.4) > Chloroform (8) > Trilene (9) > Ether (12) > Methoxyflurane (15).

Diffusion coefficient also will be in the same decreasing order → desflurane has minimum diffusion coefficient and methoxyflurane has maximum diffusion coefficient.
Isoflurane
Sevoflurane
Desflurane
Nitrous oxide