Like most RPG gamers, I have a long history with fantasy games of many different types. I started with MERP and quickly moved on to Mentzer D&D. BECMI and 2nd edition AD&D were my group's primary games for the next decade. While we played other non-fantasy RPGs, I cannot think of any significant time spent with another fantasy game. At the dawn of the 21st century, we bid goodbye to AD&D with a marathon game of Dragonlance Classics and moved on to 3rd edition. I think it is hard, 15 years later, to remember what a revelation that new edition was at the time. AD&D was so creaky under its own weight with kits and Skills and Powers that I was regularly "doing the math" for most of my players. The sad fact is, most of my players did not actually know how to play the game. This is not a knock on them, it had become very complicated, and the rules were spread out among a whole bunch of books. The feedback from that first session was unanimous, 3rd edition was in.
Of course, 3rd edition would wind up crushed under its own accumulated mass by the end, requiring more DM prep than actual playtime. In those early years, it was a breath of fresh air. Even the layout of the rule book communicated that this version was more friendly. You could start at the beginning, work your way to the end, and come out of the other side with a complete character and a working knowledge of the game.
It was right about the time that the rules bloat started to get out of control that Castles & Crusades was introduced, but I would not encounter it for a few years.
In the later years of 3rd edition, I moved away from D&D and largely away from fantasy gaming, preferring scifi gaming instead. When we did do fantasy gaming, it was more likely to be Savage Worlds or Mike Mearls' Iron Heroes. 4th edition brought me briefly back into the fold. My initial experiences were very positive, I liked the way it played and the shorter prep time. But as my players gained higher levels, and we added more players to the group, the combat slowed to a glacial pace. We abandoned D&D right around the time I moved away.
I then picked up Pathfinder as a player. While I enjoyed it, it did not dial 3rd edition far enough back for me. There was still too much going on for everyone to track, combat was slow, and it took forever to make characters. At the same time I started running an OSRIC campaign, it was amazing how much faster the game moved. The non-value added complexities of RAW AD&D still bothered me though.
A little while after I started my OSRIC game, I had my first real encounter with Castles & Crusades at Troll Con East, and it was exactly what I was looking for. It was as fast as early edition D&D, but with all of the rule simplifications from early 3rd edition. It has been my primary game ever since. It reminds me a lot of the first year or so of 3rd edition, or Rules Cyclopedia, it is an easy to use game that feels complete.
There are many tempting fantasy games around today, Dungeon World, 5e, Fantasy AGE, 13th Age, DCC, The One Ring, and Fantasy Craft. While I am unlikely to change my go-to-game, I will experiment with many of these others.
My favorite fantasy RPG is Castles & Crusades.