Well, Solvent based the best I've had was some I made myself with the strain Crystal (White widow reback x northern lights #5), homegrown, made with butane and a 6 inch long by 1/2 inch diameter stainless tube... I know how people on this site feel about BHO and solvents though so I'll just try to forget that unforgettable sweet and spicy, lemony kerosine taste.

The best bubble I've ever had was Pineapple Trainwreck concentrate from one of the clubs around here that used to be quite on top of the hash game, their bud was very much lacking though.
So I remember this stuff was HARD as a rock, try to press it in your fingers and there was no give, it was just so hard and not malleable in the slightest. Well, put just a little piece of this stuff in the one hitter, lit the lighter, dipped it down and within a split second of the flame not-even-touching the hash, it completely melted into the bottom of the bowl (we weren't expecting it to be so melting and so didn't use a screen), instantly releasing a thick, clean, white smoke into my lungs that tasted deeply of apples, moving to a heavy sweet pine flavor and finishing off gently with a lingering lemony hash sweetness, and leaving nearly no ash!

Unfortunately this was AFTER I had the pleasure of growing some pineapple trainwreck and so I did not have the chance to make my own... Someday I will though, Trainwreck is my favorite strain of all time, and anything crossed with Trainwreck becomes heavenly in my book. :-)