Strin th or string th?
String th for me, in Arkansas.
Strength. The vowel sound in my speech is e, not i.
I pronounce it as spelled. No ‘i’ sound. Rhymes with “length.”
Streng-th. We don’t pronounce 'e’s as 'i’s here, either.
Stringth, here in Houston.
Yeah, but some folks say “lenth” as well. 
And some say “height-th”.
Streng-th in my neck of the woods.
St-reng-th
I mostly say strenth, with just a hint of the g. Closer to strainth.
Streng-th. Although I have heard stren-th around here as well.
I pronounce it the way it’s spelled, with an E and a G.
Mississippian here, I say it the same as the OP. String-th.
Strankth.
Strank rhymes with ‘stank.’ So… closer to short-e than short-i.
I think it’s a Buffalonian thing.
String th, Mississippi.
Here in Boston, it’s with an e sound, not an i, and with the g pronounced.
I pronounce it somewhere between streng-th and strenkth.
streenkth
The preferred pronunciation is w/ the “g” included, but w/o the “g” is also acceptable.
When I was growing up in Brooklyn, the preferred pronunciation was “Shtrenth.”
“Hey, you know, Paulie, that strunzz’? Man, he’s got some shtrenth on 'im, don’t he?”
Since you seem to be asking how others pronounce “strength” in their respective areas, this thread belongs in IMHO. I’ll move it for you.