Luxor--not nice these days, not great location.
Desert Rose--I have frequented Vegas 35+ times, have never seen it, have never heard it mentioned on other boards. Not that it makes it bad...but the locations isn't the best. It does seem to get good reviews on Trip Advisor. But it is showing $85/nt for your dates...Can't believe it is worth double the price of the other places.
Flamingo FAB room--new carpet & linens...same old furniture. Underwhelming reno.
Flamingo GO--room not bad, but we had a couple hallway cleanliness issues that took DAYS to clean; I heard they are better now. (we were there 2 yrs. ago)
Ballys has the best location (dead center); north tower rooms are largest & nicest of your choices (GO room is close, but not nearly as large). It is where we have stayed more than any other--and we have stayed at Wynn, Caesars... we just generally get best rates at Ballys or Harrahs. (South Tower rooms still huge, have great strip views, but very dated furnishings)
Bills has a great location, too, but rooms aren't as nice as Ballys north tower, and rooms don't have safes--a deal breaker for me.
I TOTALLY recommend staying on the strip--you will rarely regret it. Even as often as we go (4x/yr), we prefer the strip, central. Vegas is SUCH a walkable city--unless you want to go somewhere specifically off the strip, a car isn't necessary (though for 8 days you will probably want it)