Can't comment on Grolsch much, but since Stella's been mentioned frequently in this thread..
I was an expat in Belgium earlier this decade. Belgium had two mainstream beer brands, Jupiler and Maes. Red bottle or Blue bottle. If you weren't drinking a strong Belgian ale, you drank either a Jupiler or Maes (they laughed at the "light" beer concept). However, Jupiler made a cheaper beer that very few of the locals drank but they exported as a luxury beer...Stella Artois. I always chuckled that Americans believing that Stella was premium was like Europeans believing that Miller High Life was truly the "Champagne of Beers".
Random observation: In the beer capital of the world, the most expensive beer at the store was Corona. I assume due to import duties/taxes.
Another random observation: Beer prices were generally consistent across purchasing locations. Yes, you could get cheaper prices when buying in bulk, but a single Duvel at the grocery store, corner shop, restaurant, bar, was always in the 1.5 to 2.5 euro range. No insane bar/restaurant markup like we have in the states. I miss drinking singles in public alongside a canal.
Related to above: I took a day trip to Westvleteren Abbey to drink the supposed best beer in the world, Westvleteren 12. It was as amazing as advertised. It was also only 2.5 euros for a bottle, despite the limited availability.
Random Belgian beer joke:
The owners of Heineken, Jupiler, and Duvel walk into a bar. The Heineken owner orders a Heineken. The Jupiler owner orders a Jupiler. The Duvel owner orders a water. The Heineken and Jupiler owners laugh at him and say "Is your beer so bad that you won't even drink it in public?" Duvel owner responds with, "Well since you both ordered water, I thought I should as well."
This concludes my trip down Beer Heaven memory lane.