I'm probably in the minority, but I like both places. Sci-Fi has a great, unique atmosphere. It's worth trying once just for that. I will admit that I hated it the first time I was there; the food was terrible. However, I haven't hated it since, so I'm not sure what the deal was with that. The food certainly is not gourmet, but I have found it entirely edible and even enjoyable, especially when paired with the surroundings.
I know Mama Melrose has received its fair share of unfavorable reviews (well, pretty much every restaurant has...), but I honestly have never had a bad meal there. As with Sci-Fi, I do not enter thinking that I'm going to be enjoying a 5-diamond meal, but I've always liked what I have ordered. Maybe the sangria made everything more palatable?