A lot of good mentions in here.
Just to add, as far as the people who changed overtime that I don't mind the change, would be Lloyd Banks. His voice ain't as deep as this and punchline oriented....
....but I do like the more technique/precision in his rhymes with something like this
Voice changes that I hate, Eminem, Lil' Flip, Plies, and Shyne. Plies is the most tolerable, which shows you how bad the others are. Plies had a semi laid back flow on early tracks, and combined with his simple flow, you could predict pretty much what he'd rhyme next, which I didn't mind
But since 2010, he's rapped with this stressed hoarse type flow that's very hard to listen to, like he needs to take cold medicine or something....
He has had some cool tracks even with that flow though (Rich nikka shyt, FEMA, Ritz Carlton).
Shyne went from sounding similar to Biggie, which was cool...
....to getting released from a long jail bid and rapping with one of the most embarrassing flows you could ever hear
It was so awful Game was even able to Shang Tsung him too
We all know how awful Eminem is now, trying to be so technically proficient but not at all being able to make an actual good song now, what he's basically been doing since parts of 2005 til now. He went from sounding like a traditional 00's white back pack rapper....
.....to sounding like AZ....
.....to rapping what would become his signature, peak, and best flow between 1999-04
Lil' Flip always been my dude, but his flow has changed so much he's pretty unlistenable. Loved how cool, laid-back and nonchalant his flow was. He was very easy to listen to
After 2005, Flip became a chore to listen to. He started rapping as super gangsta trapping Flip and left that cool fly Flip far behind. I had his 2007 double album, and though there were some songs I liked, that old Flip was missing. For every song like this that somewhat reminded me of the flow he used to have....
.....there were like 10 tracks like these that simply weren't that good