Some of the things I discovered...
Of the characters with known info (none of the Arrancar or Vizored have official stats so far), at 188 cm (6.16 ft) Renji is one of the tallest human-sized characters in Soul Society. (FYI, his weight is 78k/171 lbs.) This excludes characters like Komamura and Jidanbou. If you consider Omaeda "human-sized", he tops out at 210cm (6'8") which is taller even than Zaraki at 202cm (6'6"). Other than that, only Shunsui at 192cm (6'3") is taller than Renji, tho both Ukitake and Isane are within a cm of his height. Incidently, Renji is the same height as Don Kanonji. :-)
As for the Karakura crowd, Chad at 197cm (6'4") dwarfs pretty much everybody. Ishida comes in at 171cm (5'6") and 55k (121.5 lbs) while Ichigo at 174cm (5'7") and 61k (134 lbs) is a bit taller/heavier.
Just thought I'd share those interesting tidbits. If you want info on other characters, just click the link. They're in alphabetical order.