I have friends, but only 2-3 who would want to play D&D
Is that even enough?

I'm playing Baldur's Gate EE with friends over THE INTERWEBS. It's like DnD, but with graphics and bugs.

Oh yeah, Baldur's Gate is also decent (at least the older ones).

2-3 friends, plus yourself. 3-4 people, definitely. It's not ideal, but it would certainly work. D&D 4E assumes five players and a Game Master, but there are plenty of rules to balance the game for less players. D&D 3.5 assumes 4 people and there's very little help to find since the game is a beautiful mess. It's art, really. As for GURPS and Savage Worlds, I have no clue since I haven't played them myself. 3 players + 1 Game Master is, in almost all cases, enough.

TeamLiquid DamageReduction: Yep, I think you'll be fine.

EDIT: After reading Savage Worlds a bit more (I have the Deluxe Edition), I think it just might be kind of perfect. It seems fun, very odd, fast paced and you can play any fucking setting you'd ever want to from paleozoic era to heat death of the universe.

So what does this "Game Master" do? I assume I'll be the one taking on that role.

The Game Master or 'GM' takes the role of the story teller, its there job to create the universe for the players, they set the rules, tell the story, play as the enemies, answer the questions ect. Its usually the person with the most experience and knowledge.

Anyone played 'All Flesh Must be Eaten' I did a couple of sessions of it and it was kind of interesting but I couldn't workout the combat.

I've heard of AFMBE, I haven't actually read the rules for it. Supposedly a pretty good system, it was suggested as something to be used if you wanted to do a Walking Dead-style roleplay. Combat is often annoying in roleplaying games, because more likely than not the rules for combat are completely different than the rules for the rest of the game which sucks. I've been thinking of ways to fix that, believe you me. (there are systems that take care of it, but I'm not entirely happy with those either)

But yeah, as Cox said. The Game Master is essentially your game's engine and programming. You make sure everyone's having fun whilst simultaneously torturing them (jk). When it comes to me, I'm the GM because I have a bookshelf of RPG books. That's how it usually ends up...

So did we succeed?