I have actually seen all of shark attack 3 it was pretty good in a bad way. It come as part of a creature feature box set, which are always normally good for the B movie category. A few others to check out would be Spiders 1 and 2, crocodile 1 and 2 also.
After going on a creature feature binge I then saw an advert for Starship troopers 3, Having enjoyed the first one found the second to just be pretty boring, I went ahead and got it anyway. Let me say Starship troopers 3 managed to enter a new level of cheese covered action.
Thinking Starship troopers 3 couldn't be topped for B movie quality and humor, The most recent B movie I watched was Casshern, It is by far the funniest thing I have seen in a long while. It is completely random, makes very little sense and once you get to the middle of the movie it hits you something so unexpected even for how random the movie was up until that point that I was in hysterics for a good 2 minutes after it. Watch this one with friends it just makes the experience so much better.