I have the Palm Pre, but have had the Blackberry in the past and a few at work have the Droid. I honestly don't think you can go wrong with either. The Blackberry is BY FAR the phone of business travelers and stuff and the Droid is probably built more around being fun/entertaining, but will still provide everything you need as far as business goes as well.
I think you have narrowed it down to two excellent phones, good luck! I LOVE getting new phones and very rarely go more than a year with the same phone, but for my money, this Pre is the most phenomenal phone I've ever had my hands on, I absolutely love it. And say what you will about Sprint, but their coverage and their plans are the best around. Plus, I like to support the home town carrier here in Overland Park. :clap: