Greetings all (and Lee0506!)
Thought I'd take a moment to provide my 2c since I have been living the res life of late.
Courier: My first ship dedicated to combat, even if it is multi-role by definition. Also the first ship I swore I'd never sell and still occasionally fly for kicks. After many hundreds of hours in other ships, my Courier, Dinghy, still holds the record for most combat bonds per hour (5.75mil), so don't let anyone tell you another ship is more cost effective for grinding credits via combat. I believe it was done with dual Gimbaled Beams and fixed Cannon, harrying prey in an almost zoom and boom style while waiting for my temps to drop. The problem with a Courier in RES is its ability to finish the job quickly, limiting your ability to take on entire wings solo. She shines in a CZ where you can chase the fuzz-ball and assist with kill after kill.
Vulture: A solid contender, but I found myself parking Venator after a time. She is sturdy and consistent. I would not quite call Vultures boring as some others have, considering my only combat-related death happened in one. That is the opposite of boring. You just have to keep a close eye on your radar for new NPC's, and keep in mind that you can't outrun most hostiles. I honestly feel like she fares better in RES than in CZ, where you get to pick your fights 99% of the time.
Python: This is the ship that taught me that min/maxing builds is completely unnecessary to have a good time in E:D. I take the exact same loadout to CZs, RES, trading, bounty hunting, assasinations, pirate hunting missions, smuggling. You name it, and my Pequod can do it with a smirk. She's the ultimate multi-purpose ship, and she's my first choice when I have no idea where the night might take me. A Python is a sound ship for RES, able to handle any single target you might come across. Maneuverability means you will have to actually adopt a separate style of combat for large ships (where you can stay on them) versus small ships (FA-off), but that actually increases the interest and skill factor for me. While I find the Python to be the fastest hull-killer of the ships I take to a RES, I do find some limitations with targeting wings, where I tend to have to fully commit to one ship at a time. She's just not quite maneuverable enough to engage each wing member effectively.
FDL: My current RES ship, Impertinence will be with me for the foreseeable future. I took my lessons from flying the Python (don't stress about maximum damage output) and applied them here. She is maneuverable, fast, and she allows for FINESSE and PANACHE. I regularly kill Elite Anacondas without taking a single shot. Wings of 3? No problem. This morning I took on two 3/3 wings simultaneously. Anaconda with two Asp Explorers, and a Python with two FAS. And I run pulse lasers only. My method of combat with the FDL is to completely ignore the hull. With pulse lasers, you can typically strip the shields on any large ship with a single capacitor charge. The second (occasionally third) charge will wipe out the power plant. There is an art to positioning yourself, but once you have it down, your trail is littered with dead ships still showing 60-70% hull. Once all threats are neutralized, you circle back to finish the job.
Coriolis: ImpertinenceI do think I'll end up trying out a FAS, and possibly some day a Corvette. But I'm currently having too much fun with my FDL to worry about it! The one thing I have learned through all of this is that 'better' is often a very small variation of success. They are all great when equipped to take advantage of their strengths and flown within their limits.