Every home is different and each person has a taste all to their own, but you have to admit that some homes need black dining room sets. This is even truer for a modern home where you need to add that extra something, black furniture is quite often the best choice. They will give the room a nice clean look and add the class that you're looking for. As far as shapes, styles and designs, you can find black dining room sets in almost any style you can think of. Cost wise they are equal to any other color, but will depend on how big the set is. Figure out your budget and size requirements before you get too far into deciding what you want. Don't forget to take into consideration what you'll be using the table for including any guests you'll have along the way. As for the shape of them depends mostly on your taste, but keep in mind some rooms will require specific shapes to best utilize the space. Another thing you can do if your one to throw parties on occasion is purchase a table that has a leaf extension for the added room when needed. An option you could go for if you like the modern look is a black metal set with a clear glass top, or even one with a black metal top would look great. Or, if you prefer a black wooden top works well too. Often these sets come with cushion black metal chairs that are quite comfortable. But, if they don't have cushions there is always the option of making your own. You'll find these types of sets are great for anyone that want black furniture, but is looking for something that is lighter looking and not as bulky as a solid wood type. Keep in mind that glass tables don't have leaf extensions, so pick one that will be big enough to handle all your requirements.
On the other hand if wood is what you like then a natural black hardwood or one that is stained black is an option. Keep in mind that hardwood is expensive especially a natural Blackwood, but it will last for many generations. Or, you can opt for a cheap imitation veneer wood that comes in any color or style you like. Its true black dining room sets will not fit in every home, but for those that know what colors go great with them you can have one of the classiest dining rooms around. Remember to replace all furniture in the room to match your black set or at the very least it should be made of glass. Adding in any other colored furniture will clash with the black and take away from the effect you're trying to create.