Re: hotels in islamabad /rawalpindi area
Well, the term 5 five stars is used quite loosely here. Eventhough there isn't any official standard as to how a hotel is ranked, i think all those hotels would be something along the lines of 3 stars at best. But rest assured, they are by far the best hotels in Islamabad.
As i said earlier, i've never really lived in any of those hotels but according to my knowledge, i think Marriott would be a better fit, simply because its closer to the centre of the city and not right in the middle of it. Holiday Inn, eventhough an excellent hotel from the inside and has nice service aswell (my sister's wedding also took place in this hotel) is right in the middle of sector G-6, which is quite a hectic area to say the least (by Islamabad's standards anyways). Serena is probably the best hotel out of all three, actually most definitely is, i personally don't like its location. Seems too far away from Islamabad.
My choice would definitely be Marriott.