If you are looking for points, always do a military victory. The type of victory condition acts as a multiplier (I don't have the numbers at hand, but I have seen them on the forums before) and military is the highest multiplier. Also, it is my understanding that you keep collecting victory points for research even after you have fully researched the tech tree.
As a side note, the multiplier for difficulty level is not that great and is probably not worth it at suicidal. You will note a lot of the top players don't play suicidal....I do, but the extra bit challenge is worth more to me than the points. I suspect that is true for the others running their games cranked up.