An exhaust sound is a fine art to get right. The engine capacity fundamental pattern of operating means that the CE is going to sound higher pitched and tinny and not great unless you add some major changes to it. Just like food, everyone has a preference on what sounds good too, so rather than that ill give some info on what does what;
Larger diameter pipe = louder, and somewhat deeper note
Longer pipe = deeper sounding note. Can reduce the rasp note to a small degree.
Muffler = the most common and well known part, and this muffles and dampens the sound. They have different internals, from multi chambered sections for full sound dampening to straight through race style designs. Larger unit = generally better at dampening the sound to a lower note.
Resonator/hotdog = used for cancelling out certain ranges of sound pitches. Some mufflers act as resonators depending on their makeup. Generally speaking, the unit length will determine the sound frequency to cut out @unclepaulie
may correct me on that.
Cats = for emissions. The cats are also the #1 reason for raspyness. More cat cells (like the oem 400cell or whatever it is) means more rasp, but only to a degree - some engines will output absolute hot trash sound and the cats actually help to blend that.
For all the above, the material make up will change how it sounds. Good brand mufflers use good quality packing materials and leave a good sounding note, cheaper units are thinner and less dense, and sound higher pitched and tinny.
My ideal exhaust setup would be full mild steel 2.25" system, or 2.5" if the shop is lazy and doesnt keep the smaller size in stock. 4-2-1 Extractors (or a short 4-1, but any version will do if you can find it now a days), a 100 or 200 cell cat to help chop the sound. An 18" glasspack resonator if you can budget for it to help the rasp of the cats, and have it as close to the cat as possible, and a decent straight-through chamber muffler into any tips you want.