If upkeep and money is not a big factor in your decision, I would go with an aquarium. But, it’s your decision not mine! Terrariums are cheaper, and after setup the only upkeep is watering every few days in the case of an open version .
While with aquariums.. there are a lot more variables involved which can be interesting or exhausting depending on your personality type. I’ve skipped both options actually, but I wish I had the patience for an aquarium.
Instead, I have Gretchen. My house plant. :p
But, I’ll happily watch videos of large aquariums like the one below.