Jackie Brown is very underrated, IMO and True Romance is probably his best writing job. As far as pure Tarantino, you can't go wrong with 'Dogs.
The main "Q" problem has been is "borrowing" of others' work. Much of Pulp is Roger Avary not Tarantino and 'Dogs is pretty much ripped from the Ringo Lam/Chow Yun Fat movie City On Fire. At least he admits to his blatant theft and the outcome is generally entertaining.
Comfort the afflicted, afflict the comfortable.
If you're gonna be dumb, ya gotta be tough.