Played them all and they are all good but for me, TZ and TAF are better games than TRON. TZ would be my choice and was actually -- I now own it.
You asked why? -- You answered it yourself -- TZ is complex and packed with great shots! More so than the others in my opinion although TAF is pretty good as well. They are both Lawlor games and I'm a fan of Pat's designs. TZ had many things that were a first in pinball as well.
Or -- you could just get a brand new Iron Maiden!!
Have fun deciding