His 18 centuries in Tests:
1)278 vs Pakistan against Umar Gul, Tanveer Ahmed, Mohammad Sami - arguably one of his worst hundreds. Pakistan forgot how to field, umpires forgot how to umpire (was out twice at least before he crossed 100).
2)217 vs India against RP Singh, Irfan pathan and Sreesanth, walked in when SA were about 50 runs in front with 6 wickets in hand (first innings)
3)164 vs Pakistan, walked in when SA were about 40 runs in front with 6 wickets in hand(first innings)
4)169 vs Austraia, walked in when SA were about 340 runs in front with 7 wickets in hand(second innings)
5)174 vs England, walked in when SA were 143/4 trailing England by 60 runs
6)178 vs West Indies opening the innings
7)163 vs Aus, came in when SA were 120 odd ahead with 7 wickets in hand (first innings)
8)160 vs SL from 261/3
9)185 vs WI from 283/3
10)129 vs India from 396/3
11)121 vs Pakistan from 107/3
12)114 vs West Indies opening the innings
13)109 vs England as an opener in the second innings*
14)104 vs Australia out of a total of 220*
15)103 vs West Indies from 374/4, leading them by about 240 runs (first innings)
16)103 vs Pakistan from effectively 300/3
and the two aforementioned innings vs Aus and India respectively. I know a list such as this could be said to be misleading and it might be, but there is definitely a pattern to his centuries. A lot of his centuries seem to have come when two other batsmen have also notched up tons in the same innings. You could flip the argument and argue it isn't his fault that his teammates are so good but meh, I dunno. Too many soft runs for my liking.