I know this might sound a bit weird but one of the best depictions of Tails we've had in recent years was in Sonic Boom to me.
He's not just a coward or a plot device. He's a naive kid with an insanely high IQ and that's one of the reason I love this show so much.
An example that comes to mind is when Eggman is complaining that a 5 vs 1 isn't fair so they all have to fight him individually and he wins against Tails by using his own invention against him by complimenting him on it.
Yes, Tails made the crazy smart device but let his guard down through compliments because he's an actual child. (Well, ages are a bit ambiguous in boom but I just go with canon)
Sonic Boom doesn't always have the best characterization (looking at Knuckles but it's okay because Boom Knuckles is the light of my life) but they did good with Tails.
Also, look at his stupid smirk after trapping Sonic with the most convoluted trap ever . How can you not love him?