Well, I love it. When people ask, I tell them it's "so bad it's good." The dialog can get hilariously awful, and you can tell the cast KNOW it. They'll take an ordinary line, say it in a really strange way, and I won't be able to stop laughing. The special effects usually include close-ups of ordinary animals that are supposed to look big... and the main villain is a slutty witch who has the hots for our hero, Sinbad (despite the fact that he killed her father). Really... what's not to love? It is continuously entertaining.
I also liked the fact that Sinbad wasn't your typical hero. At least... he didn't LOOK it. He was kind of scrawny, and looked like an average guy; like an ordinary sailor. He didn't have super-strength like Hercules, or any weird superpowers... he was just a sweet, caring guy, who liked to help people. The drastic change in his appearance for Season 2 was just odd and unnecessary, and another reason why I much preferred the first season.
But the main reason I kept watching this show was because of the ongoing relationship between Sinbad and Maeve. I liked the constant bickering, and the way they continuously denied their feelings for each other... even though every member of the crew knew they were just dancing around their feelings. Despite all the cheesiness of the series, they felt real to me.
My only real gripe is that Maeve left after the first season... and with the entrance of Bryn, I quickly lost interest. I would have been happier if they had at least kept Maeve's character, and just changed the actress.
So in conclusion, I consider the first season the only one worth watching. For me, Season 2 does not exist.