I've only read The Silmarillion which obviously touches on all 3, but I have not read the individual novels. They've all been on my to read list for a while. I think I may reread The Silmarillion first though since its been 5 or 6 years since my last read.
I've been meaning to reread The Silmarillion for a long time now. It was a slog for me the first time, but I was in high school. I think I'd appreciate it more now
I'm sure the first 10-15% is still a slog as it goes through all of the iterations of elves as they broke off from one another on their way to the promised lands, but after that it is amazing.
I read The Silmarillion again recently and have been going through withdrawals. So good. Part of the reason I'm interested in these 3.