Here's a great compilation of information from reddit, ranking the various heroes, talents, etc.
If you've ever wondered:
1. which heroes are good in each game mode
2. which talent(s) are good for a particular hero
3. which heroes should i consider for a particular talent
4. which enchantment should i place on each hero
5. which traits should i put on each hero
6. which heroes should get destiny upgrades first
It isn't 100% up to date with the latest talents, and may get out of date again when new heroes are released, but they try to keep it relatively updated.
Also some people may have a different opinion as far as where to place certain talents & crests, etc., but this is a really good starting point. Use this information as a guide, but feel free to make up your own mind. Also note that F2P players can't/shouldn't wait for ideal talents to place on each hero... if you aren't spending cash on the game, it's better to take a useful talent and just go with it, instead of waiting potentially months/years before you roll that perfect talent for that one hero. Big spenders can be more picky when placing talents/enchantments/traits, etc.
Also, here's a nice chart ranking each hero in the various game modes: