Rest assured, attending any of these S.F. parties held on the marijuana smoker's unofficial holiday of April 20 should result in a world-class contact high -- not to mention beats worthy of holding a limited attention span. There are no seeds or stems in the bunch. But in order to wager on which green parties will be the ultimate in extreme stonerism -- in other words, the 420-est of these leading 420 parties -- we're weighing out nuggets from each. Join us for run-down of best options for getting hella blazed in S.F. this Friday:A$AP Rocky X Black Scale 420 Party at Mezzanine Asset: With songs like "Purple Swag" and "Get High" among his most popular, this rapper has intrigued listeners from coast to coast with a hybrid of Harlem style and Southern intoxication. People will surely bring their finest confusicants. Handicap: A$AP Rocky's double-booking on Wiz Khalifa's "Bake-Off" at Bill Graham Civic Auditorium means he can only be called a "host" here. It also means he might have difficulties remaining conscious enough for this second gig of the night after he's been smoking on the West Coast for a few hours. Bring in The Holiday with South Rakkas Crew at Som Bar Asset: Lauded DJ/production duo South Rakkas Crew -- half of which blew past an early career making pop hits to produce blazing cuts like "Renegade Rasta" -- will put those earworm hooks and rhythms to more irie use. Handicap: Host outfit SF Reggae promises to "blaze the roof off" this tiny venue and, well, that sounds kinda dangerous. Moonalice at Slim's Asset: You can be right there singing "It's 4:20 Somewhere" with this homegrown act. Plus there's an art show of their concert posters -- the band makes a custom one to commemorate each show -- for aiding hallucinations. Handicap: A presumably older crowd may not be packing the most potent stuff. 420 Stones Throw Showcase at 1015 Folsom Asset: A live performance from Souls of Mischief -- who've soundtracked many generations' stoned high school careers -- is sure to attract a 420-friendly crowd. Expect the best in Bay Area weed classics. Handicap: The venue is not historically known for having an extreme tolerance for smoke, although one might guess that it'll be a little more relaxed for this one night. Wiz Khalifa at Bill Graham Civic Auditorium Asset: Local rapping weed maverick Berner is an opener on this show, billed as the "Bake-Off," and he has been known to toss ping pong ball sized buds into the crowds on any given Sunday. Handicap: Wiz isn't as generous with his paper planes. Maybe because this is an all-ages venue, making the certain debauchery that will happen here that much more debauched. Conclusion: Oddsmaking Since our own lungs still somewhat ache from the secondhand smoke sparked up at Wiz Khalifa's appearance at the Bill Graham Civic Auditorium last June, this is our vote for the 420-est of the 420 parties. Just watch out for the kiddies.