I installed these H264 codecs:
Cyberlink h264
CoreAvc
FFdshow

The cyberlink and coreavc work good, but ffdshow seems to drop many frames also of the CPU usage is near 70-80% like the other codecs with some above 90-100% and with a low memory usage at about 700 MB.

The only thing is that you have to tweak a little to reach a good result.
Not all the codec make hardware acceleration with coreAvc i obtained the best results going from 22 fps to 38 fps with hwacceleration.
For the best results I putted the buffer in timeshift to 100 MB, minimum buffer full to 500 KB, video chace to 15 MB, and max record speed to 25 mb.
Then on the codec window I enabled hwacceleration where possible.

The only real problem is i' m not able to record a good ts from h264 channels. If someone can help i will be very grateful.

I'd like to test elecard h264 too, but it seems there is no trial version like the Ele mpeg2 codec.

Hoping being helpful for the ones have problem on viewing hd channels I will very grateful if some one give some other tips and tricks here.

well, looking on progdvb website I found Elecard h264/AVC codec.
Unfortunately like for ffdshow codec my cpu have too lees power so I can only see 12 fps but should be normal becouse on recomendation elecard say minum hardware is a dual opteron 270 (and I have only an operon 175).
So to use it should use a quad core cpu.
But quality seems good.