I started with the elmarit 28mm then picked up the lux 50mm, mainly for people and low light shots. The elmarit is great for landscape but a little too slow to be used in low light, so I recently picked up the summicron 35mm. I like the 35mm as it's wider than the 50 and faster than the 28. I may trade / sell the 28 for something wider down the road but I'm pretty much set for now, as I don't really like shooting with longer FLs than 50.
Mijo, would be interested to know what you'll end up at the wide end...
Right now, it is still the 28mm I'm considering -- either the elmarit or cron.
I own 28, 35, 50 (three of them), 75 and 90mm lenses. When I leave the house in the morning, its invariably a choice between one of the 50s as an only lens, or occasionally the 35 on the camera and the 75 in a pocket. More than two lenses are pretty much restricted to actual photo outings.