2008's best JCS'er:
Snooze

2008's best CTF level:
Sunken Realm by PurpleJazz
This was real close (with NScar, CotS and NiN), but this was overall the best.
Either way, I do believe I'd go with CotS if not this, so PJ wins here.

2008's best Battle level:
Enter the Chaos by FireSworD
Condemned wasn't too far behind, but this level is very creative and plays best, so it was a pretty clear winner here.

2008's best (non CTF/Battle) level:
Birdie Always Wins by Birdie
PSS was real close...

2008's best MP Pack:
Legends by PurpleJazz
I'd vote for both this and NA III if I could... PJ's become a fine levelmaker and he deserves credit. (The pack is of course real damn good and worth the hype, too.)

2008's best SP Pack:
Dreamless by Snooze
For the sake of fluctuation, I'll leave EM out of this vote.
If TR2 was a finished work, it'd be a strong contender. I want to see some more SP from Snuz... Preferably with clearer directions, though.
Dreamless boasts some cool effects and a strong theme.

2008's best tileset/tileset conversion:
Waste Treatment Facility by cooba
CrysilisV, The Fortress of Forgotten Souls and Gothic Cathedral are all great, but this set suits my tastes the best, so I'll go with it.

2008's most improved JCS'er:
N/A