The Daily Telegraph Crossword. The easiest of the broadsheet cryptics, and something of an institution in some Officers' Messes, although LEs are notorious for getting up early and writing anything that fits in, just to piss people off.
The Torygraph crossword makes a lot of use of service abbreviations and TLAs, so if you fancy having a STAB, (particularly when the CO walks past, so that he thinks you're a very cerebral young chap), you should know:
RN, tar, gat, re, ra, ta, raf, ac, obe
I'll add more when they spring to mind
Also a bit snidey with roman numerals, ie, "L" for fifty, and so on.
Also, all Torygraph crosswords contain at least five anagrams and one hidden word.