I only compare the versions 50/52 and 60, because they are the most modern versions an the most capable as well.
F-16C/D Block 50/52
Block 50 has a F110-GE-129 engine, Block 52 a F110-PW-229 engine.
The Block 50/52 was first produced in the early 90s an it is equipped with modern avionics (including the AN/APG-68V5 radar).
This version is a true multirole aircraft, capable of air-to-air engagements (Amraam, Sidewinder) and air-to-ground as well (Maverick, Harpoon, JDAM, Paveway etc.)
F-16C/D Block 50/52+
Same engines as above. This Block has conformal fuel tanks and is being delivered to Greece. This Block features new avionics, including the upgraded AN/APG-68V9 radar.
F-16I
This Israeli version is a modification of the F-16C/D Block50/50+, equipped with Israeli avionics and weapons.
F-16E/F Block 60 (There isn't a 62 existing yet)
The Block 60 is a further modification of the Block 50/52. The modifications are as significant that the designation has changed into E/F.
The Block 60 features conformal fuel tanks as well. As the main difference, the avionics have been comletely renewed.
The old radar has been replaced by the AN/APG-80. The engine is being upgraded as well. The E/F is equipped with the F110-GE-132.
The UAE are to receive 80 F-16E/F, Israel is to receive 102 F-16I. These two versions are the best versions. It's absolutely natural that the two newest versions are the two most advanced and the best. (Otherwise, you had to call it downgrade, and not upgrade
)