Finale is nowhere near as cool as Sibelius. Buy Sibelius.

There are people who would disagree with this comment I'm sure, however I personally have only ever use sibelius....can someone please write about what the main differences between the two are so we can make an informed decision?

The only difference for me is that our lecturer use to work for Sibelius and as a result I can't help but feel guilty when I download an illegal copy. So as a result I choose Finale.
"Sibelius is easier to learn, easier to use, and puts the fun back into writing music"
Michael Boo, composer & arranger (see:
I find Sibelius very intuitive and have attempted to learn Finale as a part of UWS B Music at the insistence of my lecturer but I can't believe how many tasks have more steps involved and simply take longer no matter how long you've been using it. Sibelius allows for many key commands which speed up the process significantly over Finale especially with the 'keypad' entry. As with a lot of software, you save a lot of money making a student purchase.