Maybe because I spent so much time with Tiger that it became the "de facto Mac OS X version" for me; if I remember correctly I think the time between Tiger and Leopard was the longest ever between Mac OS X versions. It ran on so much older hardware that I kept it running on some machines well into the 2010's. Where leopard would drive early G4 systems to a halt, they would just fly on Tiger.
My major issues with Tiger stem largely from the fact that the job I worked during that time was a small business. There was me and one other person and since I 'knew' computers, I was given the duties of an IT person for the companies computers (mainly PC) and Windows Server.
Our section had Macs only because I manipulated it that way. But Tiger did not want to play nice with the 2003 Windows SBS server. This resulted in a long road to discovering several things, primarily the fact that Apple's implementation of the SMB protocol was non-standard. It required the installation of DAVE by Thursby software before things settled down a bit. Even so, initiating more than two Finder instructions at a time would cause a beachball and the only way to recover was a forced restart. By Finder instructions I mean more than one copy or delete command.
Later on, I also discovered that Tiger's printserver is simply archaic in comparison to the one on Leopard.
In that job, I had a PowerMac G4 from 2004 to 2005, when the boss bought a G5. G4 went to the second person. That was the setup until 2013 when the G5 died. It was replaced by a 2010 Mac Pro. I swapped logicboards on the G5 and the second person got the G5. The G4 became a printserver, first with Tiger then Leopard, because the Mac Pro could not print correctly to the Appletalk printer on its own.
Your Daily Driver was Leopard from 2008. to 2020; why not snow leopard? It was so much better in every conceivable way; or did you somehow use a PowerPC Mac until 2020 (I remember most of them not even able to comfortably browse the current web at bearable speeds)?
I was PC until 2003, but my mom had gifted me a Titanium PowerBook in 2001. In 2003, I switched solely to that TiBook. I had no other computers. In 2009, the TiBook died (firs time). I replaced it with a 2003 17" PowerBook G4. Later, in 2010, I got a second 17" PowerBook G4. By this time I am running Leopard.
By 2017 I had acquired a Quad G5 and a 2.3 Dualcore G5. Both running Leopard. The Quad G5 lasted until May 2020 when all my workarounds finally started to fail. I was able to replace it with the 2009 Mac Pro I am typing this on. In 2025 I upgraded the Mac Pro from Mojave to Sonoma using OCLP. It's a 4,1 upgraded to a 5,1.
My typical price range when I can manage it for a 'new' Mac is $250. Apple does not sell ANY Mac for that price. So, eBay has largely been my store for Macs. Which typically means used.
So, yes Leopard. From about 2010 to 2020. As you may know, Snow Leopard does not run on PowerPC. The SL project for that I do not count and it wasn't available in 2010 in any case.
There is an entire thread about modding Leopard in the PowerPC section of this forum. Additionally, a project was created off of that thread that used a lot of those mods and packaged it all into an installer. I never used that because it came long after I'd installed the original Leopard.