I've always had very good experiences with Apple's Genius Bar, and today was no exception - unless maybe for the severity of the situation which was successfully resolved.
My computer was critically attacked through DDoS and UNIX alterations that made my system and hard drive completely inaccessible and fragmented. Despite my many attempts to get everything in working order, I repeatedly failed, and in fact exacerbated the situation by spreading infectious code to multiple hard drives. I'm not sure of the man's name who helped me today, but he immediately recognized the severity of the situation and respectfully included my thoughts in the repair process. He was able to collect the proper tools and transfer the information I needed from my hard drive, then reset my system entirely to ensure a clean slate when I put my information back later.
Also, I was impressed by his willingness to work beyond the initial appointment time without as much as a second thought to the matter. This, while still being able to effectively handle another client's computer simultaneously, and giving proper attention to both cases in a calm and professional manner.
I cannot say enough about my great appreciation. I wish I could remember his name to recommend him further, though I'm sure he's already well recognized internally. All appreciation and gratitude. Highly recommend.