Oh man, RTD likes his season arcs even more than Moffat. He builds his characters (especially the Doctor!) by season, he seeds stuff in the Christmas special and then has it come back to bite the Doctor in the ass in a vicious orgy of poetic justice two season finales later, he takes an offhand line from s1 and reuses it with a HORRIFYING TWIST in s3, and then with an even more horrifying twist in the specials... I like it. A lot. It's the sort of thing where you can totally watch it in whatever order and have fun, but it becomes so much richer when watched chronologically.

(The line to watch out for, btw, is in Dalek: Rose asks "Is that the end of it, then? The Time War?" and Nine responds with a heartbreakingly wry "I'm the only one left. I 'win.' How about that." Both of those are like... the lines that will not die and keep coming back in more and more messed-up ways from various characters.)