Currently i use https://foreverunblocked.info from pagemod.com proxies.They have both CGI and PHP proxies in them.
Very Reputable,SSL enabled, does provide new domains by just sending a mail to pagemod@gmail.com
I have used many proxy sites over the years be it PHP CGI glype watever,
Nowadays none seem to bypass the ever strong filters{ websense, K9 , bess},
some things one should observe when looking for a proxy site:
-Shouldn't be a .info { filters by default block them coz most are proxy sites}
-Shouldnt contain the words proxy or others like myspace,orkut,bebo in it. { they keyword filter those}
-On the safe side should be a SSL encrypted ones {https sites filter find them difficult to scan}
-Should be a reputable provider and provide fresh domains update {So that proxy owners dont steal our information,
face the fact domains will get blocked eventually, so its necessary to provide new ones.}
-I would recommend CGI proxy , even if they are time consuming they give the desired results.
Happy Browsing , Hope I was of some help