Europe coverage really depends on where you are traveling in Europe.
I would say that Marriott is probably the closest program to Hilton's in terms of elite benefits, points earnings, etc. And that includes free breakfast for both Golds and Plats (except at resort hotels for some unknown reason.) And in general, I've received very good treatment by Europe hotels from my Marriott Plat status. Note that most Marriott FS hotels will have a lounge and you will get access to it.)
If there are Starwood hotels close by where you are traveling, I would say that the top level elite benefits include free breakfast as well (at virtually all their hotels) plus you will probably get better upgrades (though I realize that may not be as big a sale point for you.) And getting Plat with Starwood can be fairly easy as they will do a one time status match. Maintaining Plat status with them can be with as few as 21 nights. (25 stays will get you Plat status, plus if you can get 2 of the SPG Amex cards, you will get a total of 4 stays and 10 nights credit toward renewing your elite status.) And assuming there are hotels in the areas you want to use points at, Starwood's program is probably the easiest to use points for awards (i.e. if they are selling a standard room, then they have to offer it for base points as well.) But Starwood hotels tend to only be found in the larger metropolitan areas with holes even there. It always hard to maintain elite status with a program that doesn't have hotels where you are traveling.
IGH has lots of hotels spread out everywhere, but their stay program is probably one of the worst in the industry. They give very few elite benefits and if you want to get any benefits at their top level hotel chain (InterContinental) you have pay just to join that program (as their normal frequent stay program doesn't cover that hotel chain.) Though earning points for stays is probably comparable to Hilton's.