which page ranks? building backlinks to htp://thisismywebsite.com but that same page is set up to redirect to htp://thisismyotherwebsite.com.... which ranks in google?
BIG NO NO! As soon as Google realizes that your page is a redirect, it'll get dropped from the index.
Assuming that the redirect is set up as a 301 permanent redirect, then it's the page that's the end destination. If it's a 302, then the first page. If it's a meta refresh (it really shouldn't be), then the first page you land on, (even if it's for too short a time for a human being to see) And vashie is talking through his bottom - nothing wrong with redirects.