Garry's Mod Help..

[Hutch]

GMod 9 or 10?

If Gmod 9 then you do need HL2. If GMOD 10 then you dont need HL2.

[Isphera]

1: Do I need Half-Life 2 to play? I have HL2 DM, and CS:S but i dont know if i need the SP game to play Gmod 9.1

GMod 9 or 10?

Looks like your blind.

You do need HL2 for GMod 9 since the files it uses are from the HL2 files which are only availible if you own it. You will also need CS and HL2DM and the SSDK, but since you have those, its not an issue.

If you were to get GMod 10, it is an entirely new entity and includes its own files, so you don't need HL2 for it.