Would you consider marrying an alien who came to Earth?
Note: You didn't say whether you would, just whether you would consider it. Regardless of what the alien is like, everyone would consider marrying it, it's just that some would dismiss the idea faster than others.
Now, if the question is "Would you marry an alien?" then it gets trickier. There are biological, psychological, and social issues that need to be addressed.
Biological: Not just biological compatibility for children, or umm...Kirking...but would the alien even be able to breathe the same atmosphere as us, long distance relationships can be more strained, and being separated by glass because one side has to be filled with chlorine is a very long difference logistically. Would the alien even biologically "love" the way we do? Does any of that matter?
Psychlogical: Is the alien consenting to this marriage because of love, or is it for less savory reasons? (note: this isn't specifically for aliens, humans have this problem too, but I feel the need to point it out) Does the alien have enough congnitive development that you're not taking advantage of it? (IE if the alien were at the mental level of a dog, can they fully consent to a marriage?)
Social: Does the alien's culture have a concept of marriage? Does the alien understand the magnitude of marriage in our culture? Would an inter-species marriage be legal?
I feel like this question should be more specific. If you mean "If species was the only limiting factor, beyond biological, psychological, and social differences, would you marry an alien?" then yeah, probably.