That completely depends on which race you decide to play that game, whether it's a public or a private match, and whether or not you're trying that game. That's a very broad question, It would be better if you could be a little more specific.
Human pub - Teleport, Tree, Wired, Gust, Rez, Rifle/Shotgun/Sniper.
Human Private - Teleport, Rez, Tree, Wired, Gust, Rifle/Shotgun/Sniper.
Elf Pub - Teleport, Rez (Vice versa depending on who is in the game), Smoke, Gust, Rifle/Sniper.
Human: Tele > Tree > Rez > Wired > Gust > AMG (Smoke if there is EVers). Guns; Rifle/Shotty, Sniper/pistol or Sniper/Shotty.
Elf: Rez > Tele > Glider > Gust > Tree > smoke if EVers. Guns; Rifle/pistol or Sniper/Pistol
And if i wanna noob around get easy kills:
Human: Tele > Tree > Wired > Glider > Rez. Guns: Katana/rifle, Katana/Sniper
Elf: Rez > Tele > Wired > Gust/Smoke > Tree. Guns: Katana/Pistol, Katana/rifle or Katana/Sniper.
Yeah, Jande! What Playshadowrun said! That's alright...we just get better and better while you're out making new alien friends and mining for ore, or whatever the hell you do in that game. :-)
elf...gust, tele...grenades for that azz (mapped) I buy rez 2nd or 3rd, contrary to popular belief
human...tele, wired, rez, gust, tree
dwarf...rez, tele, wired, gust, tree
troll...wired, tree, rez, tele
If some EVer is pissing me off I'll buy it later, not to use it, but to find out who is when they activate it. Then they think they're surprising me but I'm waitin' for em.
human-tele/res/gust/wired/tree/smoke/weapon/ams(assuming there is at least one tree on my team and the person is actually throwing it. If not tree is a second round buy)
elf-res/tele or smoke depending on if I have money/gust/wired/smoke(if i dont have it)/tree/ams/weapon
dwarf-I switch this up a lot depending on the game and my mood. Tree, res or smoke are all candidates for 1st round buy.
maybe-res/smoke/tele/wired/tree or tree/smoke/res/tele/wired or smoke/res/tele/wired/tree
troll-tree/tele/wired/res/smoke or ams depending, then the other.
The Three abilities on these races are what are mapped.
I quick cast everything else and can map the tech when I require it or not. Wired Reflexes is applied when there is no essence present in its slots.
Human Wired Reflexes/Teleport/Glider (The most over-powered build in the game)
Dwarf Wired Reflexes/Teleport/Glider (Teleport to be used sparingly)
Of course things like Resurrect and Tree of Life are purchased before but they're simply quick casted.
Rifle/Shotgun Weapons I use on every race apart from the Elf which carries Rifle/Pistol.
Time to time I'll replace the rifle with a sniper with funds permitting.
Moving on to order in which i Buy...
Troll Tree>Resurrect>Smoke>Teleport>Wired>AMG>GLIDER>Weapons etc
Yeah thats what I mostly do now, but you kinda need a glider for yourself too. Its very unlikely you will kill a human with wired katana, with one clip of SMG. And on Power Station its really annoying to try chase down a wired/katana/glider .
One tiny tele fail and you wont catch him again for a while