I was thinking about buying the Phantasmagoria pack while it was on sale, but I really want to know if it's worth buying both games.
I never played the first Phantasmagoria, and being a die-hard Sierra fan, I thought now was the perfect time to buy it.
As for Phantasmagoria 2, I've already seen Spoony's play-through of the game, and I thought it was great, but is it worth playing the game if you already know what happens?
So my question is this: Is it worth buying both games? (Even though I've seen everything that happens in the second game) Or should I just buy Phantasmagoria 1?

If you already know the entire story of part 2 then I'd prolly just buy the first one, unless you plan to replay part 2 down the road.
First one is decent, in that b-movie kind of way.

The first one is flawed in some ways, but if you can look past that, it's a fun diversion for however few hours it takes to complete. If you're a "die-hard Sierra fan", I think you should check it out. The second one is pretty terrible, but in a funny way - as you no doubt know from watching the SpoonyOne's videos. The game doesn't really have anything more to offer than what you've already seen, though. So, like Stiler said, it's only worth it if you plan to play through the game for yourself without Spoony's commentary (a lot less entertaining, IMO).

I'm going to get some hate for this, but:
I HEARD THAT, CURTIS!
Back to the topic, since you've already seen Noah's play through, the second one probably isn't worth getting.

I disagree with pretty much everyone. I'm a super Spoony fan, and I played the second game for myself, knowing full-well what happens in the end. I loved every second of it. I honestly think it's better when you play it for yourself, and I actually have a playthrough currently being uploaded to Youtube because of how much fun it is.