I'm a sucker for hardware stores, so you should probably stop reading here and go find a more discerning person's review of this establishment. As far as I'm concerned, if a hardware store has tools, fasteners, and sandpaper, they're good in my book. My only real dilemma in Hamburg so far is whether I should visit OBI or Bauhaus for my hardware needs; they both seem equally well-stocked with plenty of variety, and friendly salespeople. Okay, actually, OBI might have the friendlier (and more available) salespeople.
If you're an American like me, you can compare OBI to a slightly smaller version of Home Depot (and the orange color scheme means that when they're acquired, they won't need to redecorate much). There are building materials, tools, electrical, plumbing, fasteners, paints, plants, garden supplies, patio furniture, grilling equipment, even some weird stuff like rabbit hutches and aquariums.
I've bought a lot of stuff at OBI over the last few months, and the staff has usually been pretty helpful, and even puzzled with me once over what "white vinegar" for cleaning might be in German (it's "taffelessig" and you get it at the supermarket). They've got a huge parking lot in front, a little bakery at the entrance (natürlich), and a currywurst und pommes food stand in the parking lot. read more