Not the IBIS IMHO! Stayed there once and it has to rate as the worst hotel I've ever been in (excluding some in Portugal when I backpacked round there).
Just used one called the Park Inn right next door to Heathrow. Went with a friend & they did all the legwork on the internet but found it to be the cheapest & it was fine. Has a pub opposite - handy for tea as hotal restaurant expensive.