Riggan was mine during the first 4 years. 3 MVPs.
I tend to look at awards initially. 3 MVPs, 6 All Star Teams, 5 Silver Sluggers, .455 career OBP and .345 career average. Hopefully he doesnt hang around too much longer. He's 37 now and is still better than average. By next season he wont be very good at his current rate of decline.
Even for a player that enjoyed a full career, that is a hall of fame worthy trophy case. Riggan was legendary those first few seasons. If a good # of those original owners are still around when he is eligible, I think he gets in. If not, I'll have to do some heavy campaigning.