Here's my take:
Goku - Four transformations (each transformation increases attack 10%), easy cancels (>PKK, KKKK, K<K in the air), and Warp Kamehameha is super easy to combo into
Cell - Good reach, good variations (>P and neutral P strings are his bread n' butter), and three transformations
Frieza - Basically Goku but smaller, slightly different strings, and two transformations. No move like Warp Kamehameha
Vegeta - Short reach, decent variations (particularly his K<K and <KK cancels), two transformations, and Final Flash is just like Warp Kamehameha
Trunks - Basically Vegeta with slightly more useful dash attacks, three transformations, an extra death move, and no move like Final Flash
Tien - Trunks but with slightly different strings and no transformations
Yamcha - Surprisingly unique playstyle with a fast <P that has priority, a physical death move that can be used as a combo extender, and fast combos
Hercule - Tien with slightly different strings, no ranged attacks, and one death move
#17 - Has a lot of Vegeta likeness including his K<K and <KK though he has a <P with good range and Energy Field is short ranged but hits sidestepping opponents
#18 - #17 but with a less useful <P
#16 - Big guy with good reach and <P<K is a cancel with some range. His KKKK is also a cancel but it doesn't connect all the way in the front and he doesn't have the traditional PPPPE chain.
Piccolo - Another big body character with mediocre combos. He has two transformation and Light Grenade is a death move that only takes half a ki gauge
Teen Gohan - A small character who hard to combo on but has short reach. Limited combo ability but has two transformation and Super Kamehameha is easy to combo into
Ginyu - Has Goku's >PKK and K<K (in the air) cancels. <P has no range but it has decent strings. He also has two moves that boost his attack or guard.
Zarbon - Basically #16 mixed with stuff from Piccolo
Gt. Saiyaman - Vegeta but with no transformations and physical death moves that don't have much use
Raditz - Goku but with no transformations, no Warp Kamehameha, and an additional death move
Kid Gohan - Another small character (even smaller, in fact) but his neutral P has some range. He only has one transformation but his ground P+K is relatively useful.
Krillin - Kid Gohan but with stuff from Teen Gohan
#19 - Is a defensive character with some juggle ability and he has Life Drain
Dodoria - #19 but bigger and no Life Drain
Nappa - Big body character with little-to-no combo ability
Recoome - Same as Nappa except with only one death move and (hard to combo into) ultimate