Loved: 6502/6510
Indifferent to: Z80. Had one in my 128, I think I used CP/M mode exactly...Once?
Loved: M68k @ 14mhz, namely an AdSpeed I put in my A500. Made it a wholly different machine.
Hated: M68020 @14mhz in my A1200. What was the point in all those colors and screenmodes when the stock box ran slower than my A500 did?
Loved: m68030 @ 28mhz. Ahh...Now
this made my Amiga experience. I was given an 030 card for my 1200 by a friend (a DKB1204, IIRC) and it really flew, with 4mb fast RAM.
Loved: 486/100mhz, in my first PC. The whole board lasted all of a week until I blew it up...sniff...miss ya buddy!
Hated: '486/80, powered the 2nd PC. Ugh. Only served to remind me what I'd lost with the death of the first one

Hate hate HAAAAAAAAAAATE: Cyrix 6x86 series "budget" x86 compatibles. "Hey let's make a pentium clone with '286 FPU performance!" God I could tell some stories about the 6x86 pr/166 :puke:
Loved: Pentium 200mmx. Pretty much the pinnacle of the wonder years of P1 design (the 233 was a shade faster, of course, but I never had one

), and it came at a time when PC game innovation was at its peak. Go back and look at classic PC games and that's what your target CPU is/was.
Loved: Coppermine PIII 750 - I ran this guy for like two, three years. Loved every ounce of gaming goodness I got out of it.
Probably would have loved, but had a crappy motherboard: Intel P4 2.2ghz. Again, had a badly performing board. If I'd replaced the board rather than jumping to the Athlon 64, I might have had fonder memories...
Lovin': AMD Athlon XP3000 x64. Ooooold in terms of processor life but seriously? It's still going, it runs Win7 64bit (pro version) without a hiccup. Definitely gotta say this is a good CPU.
(I should point out that these are all user experiences; I haven't coded since the 64 days and that was in BASIC LOL)