I saw the 1st episode Season 1 when the series started just randomly browsing channels while sitting in a hotel room. I was hooked. Didn't have HBO (still don't) and have the first 2 seasons on DVD. When I found out it was based on books, I binge read all the books. May have had to wait on the last 2 until they were written. After reading the books, I lost interest in the HBO series when they started deviating somewhat from the books and just stopped watching.
Having a free HBO preview this weekend, watched quite a few of the episodes from later seasons and found similarities with the books enough to follow everything. Watched Episode 1 Season 8 last night, now our free preview is over, so may have to wait until the next freebie to catch up from here.
I highly recommend the books if you haven't read them. Several hundred pages each, just my type of book.