It is very difficult to say which is a good ptr because if I tell you about a particular site which pays there is no surity that you will be get paid from that particular site as that site may turn into scam so you have to decide in which ptr site you want to join
I think you could try to do intoffers, jillsclickcorner and donkeymails. These three sites are all very good and paying sites. Donkeymails are all 0.25 cents per mail and each day it would have a 0.1$ click in intoffers and for jills, you could try its offer.
The problem with most PTR and PTC sites is that you do not make a lot of money unless of course you have a very good downline and then it is possible. In general I have found that the sites which pay the most are the paid to post forums like this one. Remember though that the higher the offer per post, or click or read, the greater chance there is that you will get nothing much at all. The good sites which do pay higher amounts also have a daily limit on how many posts you can make.
intoffers is not a ptr, it is a paid to sign up program. But you would earn more in intoffers than you would earn in 2 or 4 ptr programs put together.
Trust me.. do your research based on this and see for yourself..