Dear Bro,
If the investment is done only for taking better returns not for future living then:
1- I-15,I-16,I-12,E-12 CDA SECTORS
2- DHA 3 (EX SCERNE CITY Sector A and B)
3- DHA 5 (Developed sectors / blocks)
4- Gulberg Residencia (Developed and possession blocks)
5- G-14/1 AND 2 (FGEHA SECTOR)
If the investment is needed to be made for future living in mind with reasonable appreciation in prices:
1- Bahria Enclave Islamabad (Developed area only)
2- Gulberg Residencia (Developed area only)
3- Bahria Town Phase 8 (Developed area only)
4- B-17 (A,B and C only)
All the quoted options are much secure and on ground. Avoid dreams set by dealers with a hope that after a year the area will explode. DO NOT trust that. Possession and Developed areas only should be chosen.