Firesprays (Slave 1s) are currently the most potent imperial ship…i personally love to fly two of them in a battle - it's hard to maneuever them sometimes, but they have good firepower, good staying power, and plenty of tricks up their sleeves. Another reason to get two sets of Slave Ones is to get the Stealth Device modifications…they can be put on anyone and increase that ships agility by 1. Falcons can be great together as well, but quite a bit more pricey (points-wise)
Y-wings have alot of health, and can take an Ion Cannon Turret which due to the 360 arc of fire can really mess with a enemy ship. They are slow and somewhat cumbersome, but i see them every other battle and they don't do too shabby when played well. Named Pilots are Dutch Vander who gives a free target lock to an ally, and Horton Salm who can reroll a die at range 3(?)
A-wings are very fast and maneuverable fighters. You can put missiles on them as well, and they have a generic 3 skill pilot that can take an elite pilot upgrade. They lack in firepower once you use the missiles, but have good survivability and can still do damage here and there. Named pilots are Arvel Crynd who can shoot people he runs into and Tycho Celchu who can take stress tokens and still perform actions
Tie Advanced are pretty much the Imperial X-wing. Similar maneuver dials, and they can take a missile. Same hull+shields, 1 more agility, 1 less firepower. They frankly aren't all that good, but do have alot of survivability because of the shields and high agility…they just don't tend to do much damage unless you're at range 1, and maneuver cleverly. Named pilots are Maarik Steele who is okay, and Vader who can take 2 actions per turn.
Tie Interceptors are the imperial counterpart to A-wings. Nearly as fast, slightly more maneuverable, and are the only small imperial ship with 3 attack dice. They're glass cannons for the imps, can do heaps of damage, but can get picked off in a turn if you aren't careful. They fill a much needed gap because of the 3 attack. Named pilots are Fel's wrath, Turr Phennir who can boost or barrel roll after he shoots, and Soontir Fel who gets a focus token when he gets a stress token (which is very hand with Push the Limit)
I don't know if that helps you, but there you go
6 X-wings, 6 A-wings, 3 Y-wings, 2 YT-1300
10 Tie Fighters, 6 Tie Interceptors, 3 Tie Advanced, 3 Firesprays