Car wont Start!

Im thinking of getting a custom tag for my car, "CURSED", because every time i fix one thing, another thing breaks. This time the car won't start... i turn the ignition to on, i can hear the fuel pump turn on, the starter clicking but it doesnt turn over. I took the starter out and had it tested, works fine, the battery is 100%. Anyone else ever had this problem? The wierd thing is it doesnt happen all the time. The other day i went to test it, and it fired up and was fine. I turned it off, and tried to turn it back on and i got nothing. Im thinking its possibly bad wiring in the ignition? Maybe the Clutch position sensor, but i think i can hear that clicking too when i push in the clutch, which would mean its working. Any insight would be helpful, thanks guys

Ok... starter is definately tight, when i took the starter to get tested the solenoid was still attached, so i assume they tested both... they just hooked up a (+) and (-) to the starter and pressed a button, and the starter gear ran, and it looked like it moved forward (the solenoid is what pushes the gear out to engage the flywheel right?) but i could have been mistaken. Also, i took out the ignition switch, and tested the continuity of it, the ACC, RUN, and START all tested fine, the LOCK and OFF i didnt get a beep, and it narrows down to the P2 tab. However, i turned the car on a little while ago, ran fine, turned it off and tried to turn it on again, nothing. Any other ideas? Thanks

PS. why does james dean come to mind ShiftTheDrift?