Everything would work for me... They all would work, but VLC requires more than 2x the processing power of more efficient software decoding solutions like coreavc... For people with Pentium Dual Cores and worse, VLC may not work for HD video. VLC is not multithreaded afaik, that is one of the reasons, but not the only... it just doesn't have efficient codecs in built.
I personally use media player classic hc (comes with in built hardware decoder filters for h.264 so <10% cpu usage to decode very high bitrate 1080p)
Link. Comes in 64bit too.
MPC HC + ffdshow + Haali splitter is the best solution for everything. Or MPC HC + CCCP if you are lazy. BUt make sure you don't use the MPC that comes with cccp