I've been to Gadget Show Live for the last 2 years and when I was there I got my ticket scanned by the nice people at Scan, which gave me free delivery for life.
They also use DPD as their courier and I find that they are brilliant. Send you a text & email early in the morning and give you a one hour slot when they will deliver. It beats the hell out of other courier services and I get it for free.
I've just spent the last 2 days waiting for Home Delivery Network to deliver something (unfortunately not PC related) which was a complete PITA.