Here's the problem with the question. Livingston was as rare an entity as there is in NBA history. A huge, athletic PG that had his best years in the league at 19, 20, and 21. Who can you compare him to, Magic, Penny, and who else? No one really.
He'll never be Magic, god, who will. But, there are a lot of similarities to Penny Hardaway due to early success and then a devastating injury that could linger and halt any true greatness he might have had.
But other than those two guys who is there? Magic broke the mold when it came to big young PGs. Before and for the most part after him as well, PGs that got lots of playing time in this league were not tall or young. Even 22 year old PGs chosen high in the draft tended to sit a year or more before getting some run. And none were big. 6'7"-6'9" PGs with NBA level talent just don't happen much.
Now if you just want to pick a guy that was highly touted and then flamed after a bad injury, there's tons of guys like that throughout NBA history. But someone who was anything like Livingston and had similar things happen to them, there just aren't any if you don't count Penny Hardaway.