A National Geographic story (linked) says that exploring deep sea & deep space are surprisingly similar. Given the choice, which would you rather explore?
The deep sea is really interesting, new creatures, sunken ships, and ancient ruins are often being discovered.
I find the deep sea to be far more fascinating.
The final frontier.
Let's learn everything we can about our own planet before going on to others.
All the way out in space. Big or small, a puddle is still just a puddle, and what we might find or learn from looking in it is limited to that puddle or the one lump of dirt it is on. Extrapolated, it’s like never leaving your house, or yard, or neighborhood, or country...or planet.
I think there is more to see in the oceans.
Personally? The sea. A manned trip to the outer planets would be a one way ticket. If we’re talking robotic probes, space.