Barbarian: Tier 4. I-can-hit-stuff-really-hard the class

Bloodrager: Tier 3. Everything a barbarian can do + spells. I see him as the arcane version of the Psychic Warrior.

Fighter: Tier 4. Much, much, much better than 3.5e. Still stuck with hitting something with a pointy bit of metal. Not much to do other than that. A few archetypes (those that give spells) might push into tier 3.

Cavalier: Tier 5. I-have-a-mount the class. Except if all you wanted was a mount, Druid, Hunter, Ranger and a ton of other archetypes of classes do it better.

Samurai: Tier 5. Essentially an archetype of Cavalier. Nothin gin it changes the tier.