With the new LRT extension lines, Subang Jaya residents can now take LRT-ERL to airport. From Putra Heights take the Sri Petaling/Ampang line to Bandar Tasik Selatan. From there take the ERL directly to KLIA or KLIA2.
It may cost cheaper if u are alone. For 2 pax and above, better take a cab directly.
For those who knows other interesting spots/popular destinations that u can reach conveniently using the LRT, please share. For example, to renew passport at Kelana Jaya Immigration office, one can stop at Glenmarie station (KJ27). the Immigration office is just a short walk away from the station.