Memory is subjective and I may have omitted some of the worst from this list and it's possible I'm being over-harsh in my ranking of the places I mention, but I think I've narrowed my all time travelling list of worst breakfasts to the following three places...
In ascending degrees of awfulness, in third place is the White-leaf Hotel in Bayswater, London. This is otherwise a good budget choice hotel - centrally located, reasonable room, welcoming staff and cheap rate, but it would be better if they left the breakfast out and knocked a couple of quid off th eroom rate... Almost everything was there in the breakfast room - coffee, tea, toast, butter, jam, cereals - it looked good.... Until we tried it. The butter was margarine, the jam was radioactive, the cereals were stale and the cheapest of the cheapo, the coffee and tea was horrible, aand there was no fruit.... a waste of time getting up so early. A stay at the Whiteleaf is recommended... just have a lie-in and skip the brekky.
Number two: the Hotel Malaya, Kuala Lumpur. much as the White leaf, though the quality of the fake butter, jam, bread etc. was possibly worse. And this is not a cheap hotel...
And top place goes to Sunny Beach Resort on Lankawi Island, Malaysia. Breakfast was one ban-Marie full of shitty fried mee noodles (with chicken and prawns in it) and a pile of white sliced bread, a tub of manky margarine and one of equally manky jam. There was a kettle and some crappy teabags too.
So two out of three in Malaysia - but there's a reason for that. See, we usually stay in really cheapo places and they don't often provide breakfast at all, but we just happened to stay at a couple of more expensive places in Malaysia (though not expensive enough to include a decent breakfast).
And the best breakfast ever? Maybe the Park Hotel in Cardiff, Wales. That was really nice....