my list (Score 1)

1 SGI IRIX
2 IBM AIX
3 SUN Solaris
4 VAX VMS
5 IBM MVS
6 Fujitsu Unix (forgot the name)
7 MS DOS
8 DR DOS
9 MS Windows3.x
10 MS Windows95/98
11 MS Windows NT/2000/XP
12 Palm OS
13 Mac OS8
14 Whatever an Apple II was running
15 IBM OS/2
16 HP UX
17 Cray Unicos
18 RH Linux (6.x/7.x) (currently upgrading to 9)

Man I feel old.