To Barcelona I took : 5d2 & 16-35L, 7D & 24-105, but like others said, used 16-35 most of time.
Took Gorillapod for churches - could wrap round bench backs and also useful to brace on my chest when I was leaning against pillars etc. Never used my tripod.
external drive : Rugged Lacie.
Another time, would just take 5d2,7D, 16-35L and 28-300L (recently purchased)
Took same setup to NZ, very versatile, but heavy - used Spyder belt and had both on my waist.