Best Prepaid Sim For Gprs (and Phone Calls) ?

Hi,

which prepaid SIM would you recommend for Internet via GPRS?

I would also like to use the same card for phone calls.

Will be in Thailand for about 3 months, mostly BKK.

I was using 1-2-call in April last year but the performance was

dreadful at times. Is that still the case?

Cheers, Ernie.