Anaesthetic that has a smooth induction is:
Diethyl ether
Isoflurane
N2O
Halothane
Ether is highly soluble in body tissues hence induction is slow and unpleasant. Nitrous oxide causes smooth induction but causes less potent. Halothane causes smooth and rapid induction and in 2-5 min surgical anesthesia can be produced. From padmaja 4th edition Page no 192,193
Anesthesia