In my opinion Firestar is the one of the best. Here's the list of accomplishments for him. He revealed Redtail's secret, he got Ravenpaw to a safer place where he would be happier (with Barley)and there wouldn't be Tigerclaw to boss him around, also he brought Skyclan back together and he chose the right choice for a medicine cat and a leader... He killed scourge, he united Windclan and Thunderclan to make Lionclan, He led all the clans to the lake on the great journey, He never wants to do the 'bad choice' for example he tried to reason out with Onestar about them not stealing the kits.
Plus he is such a good leader, even though some cats thought he was weak cause he let kittypets and loners into the clan I disagree. I mean he died to save the clans is that what you call weak?!?! I fell in love with him right from the start. He's is a good, kind, wise, battle-skilled leader. Even though he got in trouble as an apprentice he did it cause he knew what was write. SPOILER ALERT! I was so sad when he died, it felt like a piece of me had been torn away.

The only downside of him is that it was always about him like in the new prophecy series before The fourth cat just has to be about him. The clans always depended on him they were just like "Firestar go bring back windclan, firestar go kill him, go save that cat." After a while it just got annoying plus he always acted so honourable about it.

"Surely it is our struggle against hardship that makes us true warriors. You think fresh blood in the Clans will weaken us? A life without hardship will weaken us more."

-Firestar to Blackstar at the Gathering The Sight, page 335
Sandstorm: "Firestar. This is your last life. You can't risk losing it now. Your Clan needs you."
Firestar: "They need me to fight."
Sandstorm: "But what will they do if you're killed?"
Firestar: "They'll fight harder. My warriors have only one life to lose and they are willing to give it up for their Clanmates. I'm no different. My place is beside them."
He was always willing to give up his life for his clan. But there's a difference between being the hero once and always hogging up the spotlight.

I love Firestar but he can get sometimes annoying and always throwing his life away.

This is my opinion if you disagree say in the comments and explain why.

May starclan light your path.
-Kit