Adder -> Mine launcher
(high speed ship with Reverberating Cascade mines and Pack Hounds to annoy others) *Idea from one CMDR I forgot the name, had YT video 
Alliance Challenger -> Support
(hey, it's a "MMO", you need a "priest" class, healing beams, lock breakers, FSD interrupts, feedback cascade, etc. you get the picture)
Alliance Chieftain -> Powerplay
(a little bit of cargo space, a bit of firepower, nothing special)
Alliance Crusader -> Megaships, Scenarios
(again, some cargo space, all the limpets and enough firepower for defense)
Anaconda -> Main Large
(used for missions, material farming, and everyday flying around. That means enough firepower, decent jump range, fighter bay and SRV are a must for a all-in-one main ship)
Asp Explorer -> Exploration
(long jump range, autorepair, heatsinks, small SRV and a Mining Lance just in case)
Asp Scout -> Taxi, Courier
(all about jump range, when I need to travel around the bubble and using exploration ship doesn't feel as immersive)
Beluga Liner -> Passengers - Luxury, Long
(luxury passanger ship capable of relatively long distance sightseeing)
Cobra Mk III -> Starter Pirate
(for being an ole in starter zones, pirating noob ships with Cytoscramblers and Hammers. Hey blame it on FDEV for making pirate skin )
Cobra Mk IV -> Surface, Skimmers
(missiles and SRVs, for planetary surface base attacks)
Diamondback Explorer -> ?
(one of those ships I can't think of a good role to fill yet)
Diamondback Scout -> Stealth
(silent running hull tank)
Dolphin Passengers -> Wanted
(gotta find a better role for it, currently for transfering criminals)
Eagle -> Casual, Event
(not much I can do with it, reserved for fun events and flying with casual players)
Federal Assault Ship -> Bounty Hunting
(haz res bounty hunting, with a bit more group play in mind)
Federal Corvette -> Combat, Combat Zone
(huge firepower and survivability, the "tank" of the fleet capable of sitting in combat zones)
Federal Dropship -> Mining
(old days mining style ship, surface and sub-surface mining)
Federal Gunship -> Thargoid Incursion
(Thargoid killer with incursion zones in mind, mostly hunting scouts)
Fer-de-Lance -> PvP - Meta
(meta PVP build, PA and rails, nuff said)
Hauler -> Torpedos
(still searching for purpose of this ship, currently playing with idea of small hit and run annoying ship)
Imperial Clipper -> Pirate, Hacking
(if it's illegal this ship does it. Used to be best pirate ship in the game, gonna keep it for that role)
Imperial Courier -> Search and Rescue
(flying around, searching for black boxes, escape pods, etc...)
Imperial Cutter -> Trade - Long Range/CG | Shield tank | Deep space miner
(used to be my trade ship until T9 got buffed, now it's searching for a unique role to play, currently only used for open play trading)
Imperial Eagle -> Racer
(blinding speed of 932m/s, used for races and making people sweat in VR )
Keelback -> Multi-crew
(a peacfull multicrew ship with SLF and SRV, waiting for the day when multiple SRVs can be used in multicrew)
Krait Mk II -> Main Medium
(same as Conda, but smaller with access to more locations like outposts)
Krait Phantom -> Fuel Rat, Science
(long range rescue ship with some exploration aspects to make those traves interesting)
Mamba -> PVP - Frags
(a more "kinetic" PVP variant with PAs and Frag Cannons)
Orca -> Passangers - Rescue
(another ship not fully decided on it's role. For now it's used for rescues from burning stations, but I'm playing with idea to use it for ramming)
Python -> Mining - Motherlode
(moneymaker, seismic charges, a lot of cargo space and collector limpets with decent firepower to defend against pirates)
Sidewinder -> Casual, Event
(used more casually and for fun events, if nothing else it's always funny when a noob wants to kill a measly (fully engineered) SW only to get rails in the face)
Type-10 Defender -> Xeno Hunter Heavy
(full on Thargoid Interceptor killer)
Type-6 Transporter -> Rare Trade
(just enough cargo and jump range to do the famous Lave rare trade route)
Type-7 Transporter -> Smuggler
(not the best for the role, but at least it has decent cargo space. This used to be DBX, but it's cargo is just too small even for roleplaying)
Type-9 Heavy -> Trade - IBIFIBI
(space trucking at it's finest, practicaly no defenses, used to watch a lot of movies while flying this ship )
Viper -> Starter Combat
(ganker hunter, a surprisingly strong fighter, that surprises a lot of wannabe noob killers)
Viper Mk IV -> Thargoid Supporter
(an excuse to use Enzyme Missles, and annoy others in incursion zones, also gotta put those Xeno-Ally stickers somewhere )
Vulture -> Bounty Hunter
(a more solo oriented hunter for community goal farming)
