Hi Goblin-King. I'm not sure if you're still looking for info about these games, but for what it's worth, I disagree with HeroQuestFrance's assessment above. I think both games are great fun. Space Hulk in particular is a remarkably atmospheric and nail-biting game.
SPACE HULK - I own the 3rd edition (2009). Please take everything I say about the earlier editions with a grain of salt.
There's plenty of strategy in Space Hulk. I like to compare it to space chess. Extremely tense, scary space chess.

Games often come down to who controls a single square. There's definitely an element of chance involved, of course. Just like life... but the smarter player usually wins.
One player controls the Space Marine Terminators (big guys in armoured spacesuits) and the other player is the Genestealers (think of the creatures from the Alien movies). The Terminators have plenty of firepower, but small squads. The Genestealers only have claws, but there's oodles of them. Also, the groups of 'stealers are initially placed on the board as 'blips' (like the blinking scanner dots from the Aliens movie) until they get close enough for the Terminators to see them, so the Marine player is never sure how many he's up against. Oh, and because the 'stealers are so much faster, the Terminator player usually has a limited time to complete their turn. (However, you can play without the timer if you wish, which is good for learning the rules.)
The board is a modular affair with long, narrow corridors and a few small rooms. (And yes, it can be quite hard to fit on a dining table, depending on the mission.)
The 1st edition had dodgy-looking Terminators, good-looking Genestealers, decent components and a limited number of missions. There were a couple of expansions (
Deathwing and
Genestealer I believe) that added new weapons and missions. Deathwing is probably the better of the two.
The 2nd edition had better components, but changed the rules and is generally regarded as a dumbed-down version.
The 3rd edition (2009) has beautiful components (although I'm not too keen on the Genestealers) and returns to the 1st edition rules with a few tweaks. It includes some of the material from the 1st edition expansions. There are a couple of issues with this edition though--a few of the new rules and revised missions clearly weren't playtested properly. (For instance, Mission 2 tends to end in a stalemate unless you change the victory conditions). Usually it's easy enough to fiddle with things or go back to 1st edition rules though. Of course, it was also limited edition so may be hard to find at a reasonable price.
SPACE CRUSADE - I had this plus one expansion as a kid, and I haven't played it since then because I butchered all the miniatures for Warhammer 40,000, so I'm speaking from memory here...
Many people think of this as HeroQuest in space. Moving and shooting / close combat are quite similar, although you can move diagonally in SC. As I remember it, though, there's not much exploring and a lot more action. (No space furniture, unfortunately.) It's like a video game, complete with points earned for splatting aliens. Much more beer-and-pretzels than Space Hulk, but plenty of fun regardless--all kinds of big guns blazing away at everything.
It's for 2-4 players (up to 5 if you have the rare Eldar Attack expansion). One player is the Alien (a bit like Morcar/Zargon), controlling lots of varied creatures: Gretchin, Space Orks, Chaos Marines, Androids, Genestealers (yep, they're here too) and the Dreadnought, a massive killer robot. The others each control a squad of Space Marines.
Similar to Space Hulk, all of the enemies are shown on the board as 'blips' until a Space Marine gets close enough to see it. As HQFrance said, the Alien player also has an Event card deck to make something random and often nasty happen each turn (a monster might get to move twice, a Marine's weapon might malfunction, etc).
Most of our games concluded with the squad leaders staggering back to their spaceships bleeding and alone--the carnage in this game can be impressive.
The board is moderately modular (four 1' x 1' boards arranged into a bigger square). I tend to feel the components are a bit flimsier and less well-thought-out than in HeroQuest or Space Hulk though. For instance, the board and walls clip together with little plastic things that are very fiddly, damage the cardboard and are easy to dislodge. One cool feature of the miniatures is that the Marines have interchangeable weapons so you can take different loadouts each time.
There were two expansions, both now rare and sought after:
Mission Dreadnought (even bigger guns for the Marines - including guns on tripods! - and even bigger killer robots for the Alien player)
Eldar Attack (very rare - allows more balanced 2-player games as there's a new squad of ten soldiers included.)
I believe Space Crusade was never released in North America, which may be why there seems to be less material available for it on the Net than for HeroQuest. It was also known as StarQuest in some countries.