I have...

Jazz Jackrabbit 1 (all episodes)
Jazz Jackrabbit 1 Shareware
Jazz Jackrabbit 1 Holiday Hare 94
Jazz Jackrabbit 1 Holiday Hare 95
Jazz Jackrabbit 2 1.00g (OEM/Beta)
Jazz Jackrabbit 2 1.00h (OEM/Beta)
Jazz Jackrabbit 2 1.10o (OEM/Beta)
Jazz Jackrabbit 2 1.20
Jazz Jackrabbit 2 1.21
Jazz Jackrabbit 2 1.22
Jazz Jackrabbit 2 1.23
Jazz Jackrabbit 2 The Secret Files (1.24)
Jazz Jackrabbit 2 Shareware
Jazz Jackrabbit 2 The Secret Files Demo
Jazz Jackrabbit 2 Christmas Chronicles
Jazz Jackrabbit 2 Holiday Hare 98
Jazz Jackrabbit 2 Special Edition
Jazz Jackrabbit Advance
Jazz Jackrabbit 3D Demo

and OpenJazz if that counts!

Might fearsome list, eh! (Full Collection)