In my opinion this is the best class:

primary weapon: MP5-silencer
secondary weapon, M804A ( the first sniper)-acog
special gernade-stun
perk1:banlador
perk2:overkill
perk3:steady aim...

Note:this is a hardcore TD class, if you want to add me or if you have any question, or just want to practice add me xdeathoreox.