i'm not the worst gamer in the world, i do have a natural affinity with games just easily pick things up and rarely have problems with controls.
(music games and the occasionally badly designed control scheme are exceptions to that though.)
i'm definately not the best gamer either, my reaction time is just a little too slow for me to really excel at any FPS or compete on high level RTS games (my play style in RTS games is also a slight handicap because i like to turtle and not a great many games allow turtles to be competative.)
fighting games i do okay though mostly due to button mashing only a couple of fighting games where i've actually put time in to learn the moves and even then it's only for a handful of characters.
racing games are a real mixed bag, some i'm really good at others i can't win for the life of me.
action games i enjoy but i never play above normal difficulty.
RPG's i absolutely play to death,and depending on what type of playthrough i'm going for i'll adjust the difficulty to it, sometimes i like to make the most uber characters with the best of the best, then i play on the highest difficulty for a challenge other times i like to try sub-optimal builds for more character driven improvement etc. i usually play easier difficulties then typically on normal.
i do seem to excel in RPG's most where you can simply look at all the possible builds and create the most powerful and efficient character on your "off time", generally i do this for my second playthrough i plan out my character in advance and level him up according to plan and generally steamroll all opposition even on the hardest difficulties.
on the other end of the spectrum, music games, i just don't get it, i can do a couple of buttons but when i have to use too many different ones i just keep messing up and it's not about the reaction times oddly enough with music games i'm capable of handling that for some reason, no my hands just completely sabotage me and keep me from actually finishing songs etc.