Depends on what you want to do. I do very little smd soldering. I have the following tips:
STTC-042
STTC-013
STTC-038
STTC-144
STTC-033
I also have a Thermaltronics tip, M60H178
These cover my personal needs-smd passives to PL-259s. By the way, please don't double post, it annoys the moderators.