Oddly enough I suck at most shooters but not all.
I do fine with games like Einhander, Thunder Force 4, Lords of Thunder, Gate of Thunder, Robo Aleste and Final Soldier. I suck at all the other Soldier series on the PCE, all of the Gradius series (minus 3 on SNES and 4 on PS1), R-Type, Pulstar, Last Resort, Tatsujin, Air Zonk, Ikuraga and most other vertical shooters hand me my ass most of the time.
I also suck at the older Mortal Kombat games as the controls are borderline broken to me, along with the stiff gameplay as well. I could be a little better at 3D fighters, but not all too bad at Tekken 3, Tag and Soul Caliber 1, but that is just due to lack of practice and learning the games more. When it comes to my friends, nobody plays 1 on 1 fighters these days... just FPS games online.
I wish I was better at playing some harder Strategy/SRPG games like X-com UFO Defense, but I am excellent at all the Command and Conquer games. BTW, check out C & C: Red Alert 3 for PC, XB360 or PS3. It is one of the best RTS games I have ever played... very enjoyable. You can get it on the cheap and also don't forget to download the stand alone side game Commanders Challenge. Lol, Rick Flair is in the FMV in-game parts.