There is no competition. Lock, Stock is on all accounts the far finer film. Don't get me wrong...I *loved* Snatch, but like Mephisto said, it could easily have gone under the title of "Lock, Stock and Three Smoking Barrells"
I think Snatch
tried too hard to get laughs, but in Lock, Stock the laughs just came much more naturally.
Brad Pitt, though, did do a great "member of the travelling community" to use the current p.c. term.