I have no problem with the shark in Jaws, actually I think it looks pretty damn good still.
It's sad models are replaced with CGI so often these days, this is one of my main problems with CGI, it can be used to great affect but is far too often used simply as a tool for lazy film makers.
People talk about the Shark being bad when it jumps up onto the boat but in all honesty I've never even noticed, using a model like that means there's a very real physical presence for the actors to work with, this for me always seems to achieve better results. Just like how real blood splats always look better than the crappy CGI ones.