Sylar's original power as described by him is the ability to see "the way things work". He has somehow found a way to use this power against other people with special abilities and modify his DNA and "collect" their powers for his own through some unknown process involving the brain (by eating their brain). The process has driven him slightly mad and he refers his craving to power as a "hunger".
Some Sylar's victims are: Peter Petrelli can mimic the abilities of others. He also seems to have an empathetic ability where he may see things through others' eyes in his dreams.
Claire Bennet, High School Student and the Cheerleader has Healing Factor a.k.a "Spontaneous Regeneration"
Neo - IT Geek! Baik jua kuat firewall nya kalau inda turut kana makan utaknya =p
* more to come *