I've had 3 diversions. 2 were due to medical emergencies [made unscheduled landings to allow medical people to remove an ill passenger], the third was more involved:
Flt. AA44 on 1/12/14 from LAS to JFK departed on time and (due to tailwinds) was now scheduled to arrive 30 minute early. About 90 minutes from JFK, due to weather and mechanical issues (at JFK), the flt. was in a holding pattern (expected to last 30 minutes)--but that stretched to 1 hour. The plane was now being diverted to SYRACUSE, NY. After one hour on the ground (plane had to be refueled), the fight was to take 40 minutes to JFK; BUT (JFK still had problems), 30 minutes from JFK...a new holding pattern...there was a NEW diversion possible [not enough fuel was added at SYR]. Finally we received clearance to land at JFK. 4 HOURS late--but at the gate we had to wait over 10 minutes for them to find a GA.