I'm partial to Fluid Concepts. I personally have yet to find a rack that performs as well.
Multiple mounting options
Boards don't hit each other
Racks don't rotate
No plastic parts to pop you in the knuckles
A company that stands behind their product
Don't buy the Titan swivels...they're a waste of money on a Titan tower. Only my opinion of course.
You can check out FC at www.fluidconcepts.net
Hit me with an email if you'd like pics or additional info, I've had 4 of their racks on my Titan for the last year.