Traktor for party DJ’ing
I use Traktor Pro2 with a Kontrol S4 and Kontrol F1 for party DJ'ing and love it. Its quite a leap from simpler systems with a fair bit to remember and think about as you use it to avoid cock ups, but its so powerful you can do pretty much anything with it. This setup is used by some of the best club DJ's in the world so is it overkill for party DJ'ing? Maybe, but it depends on how you DJ really doesn't it. I don't use everything it can do but I find it helps me avoid getting bored during long sets of many hours and it lets me have much more fun playing than simpler systems.
Having the 4 decks can be a godsend and I think is the most important improvement over simpler set ups. I use one of the extra decks as a remix deck (samples) and the other to line up important moment songs like first dances, as an external spotify or mp3 player input or just as a spare deck to mix one track over the other whilst still having the other main AB deck for the next track. Once you DJ with 4 decks you'll wonder how you ever survived with 2!
The Kontrol F1 isn't necessary if you aren't interested in using looping samples etc, but if you are its reasonably priced and is great to use live with the per channel faders making it much more useful than other third party sample trigger pads.
One note is the PC or MAC you run the Traktor Pro software on – it needs to have a decent amount of power. Using a low spec machine you are likely to run into processing power problems once you are doing anything remotely complex with it.
My Traktor S4 and F1 shown in the photo have been pimped with Chroma Caps from DJ TechTools!