I watched the first two episodes of Blood and Sand and found them painful to watch and unintentionally funny, and said as much in an older thread at the time.
However, after reading many other comments about how much the show improved after the first two I went back and gave the whole series a second chance and was very surprised.
Pretty much everything improved greatly, literally from the third episode on, and by the end of the season I was totally hooked. I'm really looking forward to season two, though I'm sad Andy Whitfield won't be able to be a part of it. He brought a lot more depth to the role (and the show) than I ever would have expected at the beginning so it's a real shame he won't be there, especially since the second season should focus even more on Spartacus.