Love both the Pistols and the Ramones, but if pushed for a favourite it would be the Pistols for certain. The music scene in the UK in the mid 70's was rife with disco and the remnants of glam rock. A change was needed and the Sex Pistols rocked the music industry to its foundation, they were never the most competent musicians but Jones, Matlock and Rotten had a magnetic appeal and worked great as a unit. The introduction of Sid was nothing to do with music it was all about image, and he succeded in giving them the high profile they sought so desperately.
People all seem intent on catergorising groups into little genrés, and if thats the case i wouldn't even call the Ramones punk, they emerged in the New Wave era in New York as a straight forward rock' n' roll group. Heads down, legs apart, playing at a 100mph was always their trade mark, they didn't court controversy like the Pistols but it always found them. They released numerous albums but the songs are interchangeable (read sameish) and just seem to run for 2 mins and you're onto the next tune.
Before all you young "experts" out there ridicule my reasons i should point out i've seen both groups live (Pistols in 77)

so have a valid reason for my vote for the Pistols. It was genuinely exciting to see the music scene change so quickly and for the better. When all said and done though i'll take The Damned as my punk group of choice.