5w30 fully synthetic, What oil you use is down to you,I have no preference to be honest. Just buy the best you can.
They don't drink oil like the old V-tecs used to. Have a peek every 6k or so as a general rule. i would advise this on any car not just the Honda I-Vtec's.
Stuart as Neal said I use 5W30 silkeline pro from opie oils.
It's not cheap but the best for your engine IMO.
Lots if members use 5W40 as well if you drive in vtec a lot for more engine protect.But for better mpg the 1st oil grade us better.