Alright, here's some real relocation theory to help you out. Everyone likes a giggle every once in a while for the 'relocate inside the kooky crazy vent TEEHEEHEHE!' but there are strategically viable and worthwhile relocates that can help win the game for you. Since we're discussing relocation, lets not forget those useful places to move to.
The basic relocs will be either for area control, or for res control. It all depends on what type of strat you're going to use. If you want to lock down a hive or two and hopefully keep the aliens from expanding so that you can take out their hive quickly before they lifeform up, you'll want a good area control relocate. Examples of this type would be relocating to main aft on bast (well, at least until the b5 bast comes out and main aft becomes less important) or a reloc to temp control on lost (hard to pull off, but if you can do it, you now have two hives controlled)
The second type of relocate is for res control. This is not quite as good as the first, honestly, because it's a bit more risky. Basically you move wherever there's the most res nearby. All relocates to double res nodes are of this type. The problem with these types of relocates is that, depending on the map, you may not have much in the way of area control. For example: a big mistake people make on bast is taking the res control reloc (atmos) over the area control reloc (main aft). Sure, atmos gives you the double node and probably feedwater. But you're completely giving up marine start, main aft, and engine. They're simply too inconvenient to get to from double if the aliens put any effort into controlling them. You can't send one marine over to recap them, it won't happen. It has to be a whole team assault. Whereas with the main aft reloc, you get to control engine and refinery, and the majority of the nodes on that side of the map. Some maps though, double is a control area, because it's centrally located (caged, tanith). But if you're going for res control, that means you're also allowing the aliens to build up territory, res, and hives, so you have to USE your res control. Keep upgrades flowing and be prepared to deal with higher lifeforms and take down multiple hives with this type of game.
When picking your relocate position, consider a few factors:
1. Is there ANY res nearby? If it comes down to a crunch, there should be at least one res node within view of your base so you still have something pumping res even if you've lost all the rest of the map after a big hive assault.
2. Is base in the middle of a main thoroughfare? You want it to be. Find the main road of the map that you're on and park your base right in the middle of it. That's the importance of choke points. That's the reason that a reloc to cargo on tanith is 100 times better than a reloc to west access. The only reason to go to west access is to get a node. It's useless as far as map control. But cargo is a hugely important point. Several paths are squeezed through it, and it allows control of fusion hive and two res nodes (cargo, fusion) with another two in easy access distance (acidic, chem), and it keeps the aliens from getting from one hive to another without having to squeeze through vents or take the long way around.
3. How are the lines of fire? There's something in most comm's heads that says that a base is more 'safe' if it's tucked away in a tiny corner. No. Tight corners are good for aliens, they're death for marines. Marines want to be in large open areas (but with low ceilings if possible; make those fades and lerks attack in two dimensions instead of three). Long hallways are nice. Long distances to the nearest cover are also nice. Assaulting aliens will have a good chance of getting blasted in the back as they run out to heal. Always remember that marines are at the advantage with distance.
So, good relocates:
Bast - main aft.
Tanith - cargo (reactor is decent, but you better end the game before they get fades, reactor is a fade playground)
Nothing - generator for map control, but don't get slowed down... gen is way too easy to assault with big lifeforums; cargo for res control with two nodes and decent access to gen, plus a hive block
Veil - double is good for res control and for denial of cargo, but it's also somewhat easy to assault - try the long hallway between double and subsector for res control + map control + area control + good lines of fire - the only disadvantage is no res node in sight, but if you can hold double you'll do okay.
Ayumi - cold turn - blocks hama hive, has two nodes close by and eastern just down the hall. Easy access to both other hives. Very hard to pull off if the hive IS hamasaki. Can also be harassed to no end by a lerk sporing from the long hall that leads towards pressure control
Nancy - mess hall - of course... actually putting most of your base in the tunnel just outside mess is preferable, just keep it towards the aux gen end of the tunnel or a bb gorge in the vent up above could really ruin your day
Relocates I'd be curious to try:
Agora - analysis lab - decent for res control and more strategically located than MS. Has the advantage of big annoying BUTTON OPERATED doors. Pretty much a free kill for any big lifeform that comes in.
Nancy - cargo - just because I wonder if it's at all possible for marines to GET here without dying at game start... maybe with a really bad alien team it would be possible, but otherwise I strongly doubt it. Would be a nice area control relocate, with res nearby in a few areas, but it's mostly theoretical.
That was a lot of typing, and I should really pretend to work some now. Feel free to add your (good, not goofy) relocate ideas as well.