It aminly goes for what you look for in a grab. Like Cox said Ness has decent throws mainly bacuse he has the strongest back throw in the game. Dedede can chain more then half the cast with his down throw and inifinte a few chars like Luigi Mario, and DK. Falco and Pikachu also have good chaingrabs.

Snake's downthrow is the most powerful throw in damage. Also all of the Pokemon trainer's pokemon have good grab games for spacing and kos(Charizard having the second largest non-tether grab in the game). Ice climbers have arugably the best grab game because of their abiliy to 0 to death from a single grab, their indivual throws however are mediocre.

Overall, throws have a much less practical use in Brawl because they aren't as powerful are good to combo with as previous games, mainly they are used for spacing and chaingrabs now.

Snake's has the most potential for highest damage. Dedede's back throw actually has the highest damage with 16%.

If you're looking for an awesome grab game. Kirby or Olimar hands down. Kirby has the most damaging (non chaingrab) throw combo in the game, able to carry some character over 50%. They both have great options with their throws. Chaingrabs? Dedede is king with Pikachu, Falco, and to a lesser extent Peach doing well. Using throws to KO? Ness wins by far with the hardest knockback power of any other throw. Tech Chasing works well with Snake & G&W

Another reason I like Brawl+ Peach and Zelda can KO straight out of a thow at decent percents. 80% D-throw with Peach chains straight into Up-smash, varying on toon weight. Zelda can F-air straight out of a D-throw at ANY percent. Kirby can constantly grab and kick the crap out of the cast with reckless abandon to 80% on most of the cast and even has 0-Death combos on certain characters if he grabs them near a ledge (F-throw>U-air>F-throw>U-air>FF D-air spike = epic)