The evangelism of Signs is perhaps a little much, and the plot holes are big, but I like the film stylistically: emphatically slow, operatic but small.
I liked Signs quite a bit. The evangelism didn’t bother me, except for the moment with the prophetic mother, which was just too nonsensical. I didn’t even mind the part with the water at the end; I thought it seemed believable enough. It’s not like the aliens were there to settle Earth, they were just an unknown threat present only for a brief time.