I not sure where you flew from - LGW or LHR.
I have flown LHR to LAX so many times I ve lost count and have always found the entire crew - from booking through check in to cabin and flight deck crew nothing but helpful, polite, professional and fun - making the whole flight experience a pleasure.
Strangely the other 2 airlines I have flown with to LAX, (not counting Continental who code share with VS), were BA and Air Cananda. Both trips were a nightmare - everything from rude and unhelpful to sheer pettyness - not all of the staff but enough to make it very noticable. Mrs PW and I vowed to stick with Virgin!
Last trip was November 2002 so wouldn't think things have changed that much.... maybe an unlucky experience?
And I have no connection with Virgin, except working with a couple of guys who wife work in the admin. side of things.