I develop using all three languages and here is my preference:
1. JSP
2. ColdFusion
3. ASP

I like JSP because of its scalability and performance and it gives you the
power to use Java and its benefits. Having attended a few J2EE conferences-
it is vendor independent as it is just a specification that Application Servers
can adopt and many are like Sybase's EAServer, IBM's WebSphere, Allaire's
ColdFusion, etc. I wait for JSP to catch on fire and sweep across the web
development industry.

CF is next on my list because it is powerful and easy to use (basically no
learning curve!!) Its application server has really evolved and I was in
touch with an Allaire Rep last week and they said Allaire is moving CF completely
to J2EE compliance with backward compatibility for CFML- I think this will
give them a great edge in the App server area. One thing I would like to
point out is that CF doesn't have that small of a following. It is popular
and is getting more and more popular because of its low learning curve- to
name some companies that use CF in Intranet or Internet: Autobytel, ATT,
Lockheed Martin, Reebok, Siemens, Casio, DHL, IRS, Kodak, Pacific Bell, Wickes
Intl and these are by no means small players.

ASP is the last on my list because it does tie you to Microsoft (you can
use plugins like chillisoft but at what performance cost?) I have never
tested the peformance of ASP myself but have heard that isn't as good as
some of the application server driven web applications. Also, ASP isn't
as intuitive as CF but of course is easer than JSP.

Well, thats my two cents :-)