The best Mario Party since it's debut
The graphics are better than the N64 games; that's pretty good for a DS game. The sound is perfect and the Multiplayer is arguably the best out of all the DS games out there. You can start a whole party with only one game cartridge.
The single player is pretty good too. It will give you pleanty of things to do so you're pretty much ocupied for quite a while. There are a lot of side things to do other than party mode aswell. So if you want a break from all of that board play, there's somethign else to be found.
Mario Party DS is a game that any Mario Party fan should own as it is as good as the Nintendo 64 ones. If you're not sure whether to buy it or not, try multiplayer from a friend, you'll know that you have to buy it after that.