When it comes to "best," well "best," like beauty, is in the eye and mind of the beholder/toker.
I think what you need to do is to define "best" and "strongest" in terms of pure sativa or pure indica or predominantly sativa or predominantly indica or something somewhat close to or being a 50/50 cross. You need to decide if you want a clear soaring mind-bending head high like a sativa will give you or a mind-numbing couch-lock body stone of an indica, or wherever in between that your tastes might be found.
Until you know what you actually like and then relay that to others it is fairly difficult for someone to say they know a good strain or two that you would really like.
When it comes to levels of THC, the highest rated strain from a REPUTABLE breeder that I can think of off the top of my head is Herijuana from Sannie's Seeds.
Sannie's Seeds - Herijuana
Location: indoor;
Type: mostly indica;
Flowering: ~56 days; No feminized seeds.
Known Phenotypes:
Genetic: Herijuana IBL
Flowering time: 7-9 weeks
Harvest: up to 500 gram/m2(indoor)
Taste: sandlewood/afghani
Effect: heavy medical body stone
Flowers: They are rockhard with lots of crystals
THC: up to 25%
This fabulous indica has more then one fine qualities. This makes her very loved all over the world. Because of the high thc percentage en the narcotic after effect, she is often used as a medicinal smoke. The flowers are covered with resin and smell intoxicating.
This plant originates from Woodhorse and was perfected by Moterabel. Sannie and Moterabel work together with genes and since Moterabel is unable to breed for himself anymore. I received the seeds in 2006 and had 2 grows since to get an overall view in what to expect. After the selection we kept the seeds off the best pheno. Because the original seeds were already IBL (Inbreed Line), these seeds are also best to describe as IBL.
The plants grow fast and produce a lot of side branches, as a Sativa normally does. Because off this quality Herijuana is a great scrogg (screen of green) plant. Herijuana keeps growing for the first 2 weeks off bloom and produces golfball-like buds, even the lower buds get rock hard.
Votings of our users: Herijuana gets 7.00 of 10 possible Points in the average!
User-Generated Strain-Profile
For this strain we got input by 1 user(s). Here a short overview:
Flowering Time Indoor: 60 - 80 days (~70 days)
Stretch after the initiation of flowering: ~100 Percent
Initiation of flowering onto around 40 cm. - Final Height onto around 80 cm.
Growth Behavior Indoor: Bushy
Yield / Quantity Indoor: The crop of this strain is ordinary.
General Impression: is all together extremely good and very recommendable.
More Info: Please click here to see the full Plant-Profile!
Strain Lineage / Genealogy / Family Tree
Crossbreeds and hybrids with "Herijuana"