I am very happy with my Smart Gold cellular phone plan. I pay P1, 200 a month or roughly $30, but I get so much out of it. For its cost, my SMS costs 50% less than prepaid plans and those with smaller monthly subscriptions.
Additionally, my call rate is like 10 cents per minute to all networks. So I think it is cool. I also get an additional free 250 text messages per month. All in all, if I don't make calls, I can send 2650 sms in a month! Of course I can't finish them all. But I have tried the smaller plan at $20, but I usually end up paying almost $50 a month. So it was not feasible.
And with the plan, I get to choose a free new phone every 1 year and 6 months. So my profit would be the free phone that I get regularly. So I think it is amazing. Signal is pretty good, too.
Update On Nov 01, 2009: I recently got a Nokia E63 for free with my plan, after only 1.5 years into my plan because of early renewal. Cool, huh? And I sold my old phone for $80. So I got some money back.