My ps2 won't play games any more :( HELP?

My ps2 I swear is on like deathsbed, but it isn't at the same time. It works perfectly fine...except for the fact it never plays dvds or games or anything! *frustrated* So usually it works...like 65% of the time, and tonight I went out and rented a videogame and I brought it back home and put it in and as usual, the screen read 'disc error' ect. And I've already tried cleaning my system in the past and I've made sure the lasers are in ailignment (sp?) and a;lsjfas;lkfj I just want to play my game. So does anyone know any tips for me? or maybe tricks on how to get it to play the game???