The Best Softphone client for Asterisk

Hi All
I am using 3cx phone as a sip client for Asterisk
but does not seem do be working well
I need a best sip client for asterisk that is known to work well with it
and benefit of all asterisk features.
Any help?

I use Counterpath Bria. Works great with Asterisk and has a lot of features.
Transfer calls, hold etc…