Best games to have with Garrys mod?

I currently have no games on steam and if i want garrys mod im going to have to buy some games. I was just going to do HL2 but i was considering the combo packs and thinking about one of them too. Can someone give me a quick little list of the best games to have with garrys mod? in order of most enjoyment/moneys worth

CSS almost is a must have, Most RP’s use this and most gmod players have css too. Also EP2 is recommended. Myself i have bought the full source pack.

Everything but zeno clash

What you just said means that in order to have the best experience in gmod he must own every single game on steam… except for zeno clash.

lol

Orange Box and CSS, with them you have everything you need, also rp servers and most gamemodes use content from them.

It seems to be quite unanimous, 55 dollars it is. I know I’ll be getting my moneys worth, thanks a bunch guys.