Chosing Planets

Arid = Excellent allround bases because of a high area + average fertility. Best to grab these in orbits 2 & 3 to get 6 fertility. Arid moons are good choices too - with average area and a discount for higher end defences.

Asteroid = Great for economic bases due to the good crystal rating they have. Also make fair production bases due to their high metal. Turning these into multi purpose bases isn't a good idea though, as they have a very small amount of buildable space. The low fertility also provides challenges. They do however benefit from very cheap high end defences. Try to get them in orbits 2 and 3 if you can.

Craters = Good metal rating, but Low fertility and low area. Not a good choice to be honest.

Crystalline = Very high crystal astro: a very welcome boost to your economy. Low fert and only average metal poses issues, but IMO the high crystal more than makes up for this. Put simply - if you see one that is free, do all that is in your power to nab it.

Earthly = A good all round planet that has average metal and area with a high fertility. In any orbit these astros are worth having; especially so orbits 2 and 3. You can turn these into either Research, Production or Multi-purpose bases with minimum fuss.

Gaia = A slighty better choice than the Earthly planets due to a higher area, although much rarer. Again, excellent choices in any orbit, especially orbits 2 and 3. And again, can take their hand to any base configuration well. You also get a funky planet image too.

Glacial = Poor metal score rules this planet out for anything other than a research base (as it doesn't require metal to be effective). A high area with average fertility however does mean it lends itself to the task well. Only really of use in orbits 2 and 3.

Magma = The thing that really sets this type apart is it's 4 gas with average fertility. These would be very good bases for jumpgate locations because of the cheap energy available. Otherwise they'd make ok bases; their low area hampering them a touch. If you can nab one in orbits 1, 2 or 3 you'll have the makings of a good base.

Metallic = Poor fertility and medium area make these astros unsuitable for bases. Although at a stretch in orbits 2 and 3 they'd make good production bases. best avoided for the most part.

Oceanic = A low area and low metal consign these astro types only to the research role; they're redeemed slightly by a good fertility though. A bad choice for anything other than a research base. IMO the astro picture is quite cool too.

Radioactive = A poor fertility astro with average stats elsewhere; although has a good area. Really the only place these will make a good base is in orbit 2, with 3 solar/gas and 5 fertility - it'll give a decent base if you need cheap power. Best avoided really though.

Rocky = Widely considered to be probably the best astro type in the game, namely because it combines a good metal score with average fertility and area. In orbits 2 and 3 you have fertility 6 - and this is widely considered the best place for them; although in honesty any orbit is acceptable (orbits 4 and 5 give 3 gas, a reasonable source of power)

Toxic = The poor fertility of these astros puts most off; they do however have a good area and 4 gas. They'd make good bases if cheap power was your concern (like a jumpgate for example); and you could also afford to mod the biosphere in the long run too (again due to the readily available power), orbits 1, 2 and 3 are the best to nab these. In the short term, they're not much use though.

Tundra = Another excellent astro type. Has identical stats to the Arid, and lends itself to the same roles; just the surface is colder I guess lol.

Volcanic = Identical to the magma astro type. Same bonuses and caveats.