There have been some really good games on there throughout the time I've had PS+. Off the top of my head
Metal Gear Solid Ground Zero
Outlast
Strider
Rocket League
Super meat boy
Resogun
Styx
I know there's a bunch more. I just have to do the Google's. Point is its not as bad as people make it out to be. Sure there are months back to back where the games are weak, but I don't mind. I have plenty of retail games that keep me occupied. I look at the free games as games I should try at least once that I wouldn't have tried otherwise. Every now and then I'm pleasantly surprised. The PS+ deals are great too and they happen often. The experience is similar with XBL gwg. Side note: this thread gets made at least once every other month.