I have the powerblock elite set that goes up to 130lbs, they are nice becuase they take up almost no space and are very easy and quick to adjust.
Once you get up to the 100+ they can be a little cumbersome. Plus you don’t really want to drop them as they are obviously not as forgiving as a standard dumbbell set but do have a lifetime warranty
Whatever you do don’t buy the one’s made by bowflex. I was at sears the other day and they were selling a set of these. Just picking them up you can tell how poor quality they are, and the price… my god. I couldn’t believe they would actually try charging such a hefty price for such a piece of shit. Oh wait… yes I can.
I just went to Dick’s and bought a pair of Olympic dumbells. They hold up to 210 lbs apiece (4 25s on each side). I think they cost $30 each. They seem like reasonably well made equipment.