John, welcome to the forum! I would do some googling on this - there are a few good sites with rosters. That said, your basics are:
F40C (13 total, 2 left in layup) bought early 1970's for MILW only
F40PH (27) bought late 1970's, rebuilt recently
F40PH-2 bough mid 1980's
F40PH-2M "winnebagos" with slanted windshields, delivered 1993 to replace the BN E9's.
MP36C (25-ish) delivered around 2005, special order with 645 engine for parts commonality
F40PH (2) bought from TN railroad museum, former Amtrak, acquired for power shortage reasons
F59PH (3) former Montreal commuter, GO before that - being rebuilt now, acquired for power shortage reasons
All of above have 645 engine save for F59's, that has 710. All are 3000hp except MP36 has 3600 and F59 has something like 3200.
Also there are about 5-7 assorted switchers for work trains including one of the oldest diesels still operating - NIRC 1 perhaps?
There were once a handful of ex-CNW F's and E's in the Metra scheme used as backup but they've been gone close to 20 years now.
If you want some real entertainment, there are a few pics floating around of F40's pulling Rock Island's Harriman cars. Not something you'd expect to see.