Check this list to see if your suggestion was suggested already and see if you really need to post it.
Server Based Ideas
ZE
ZE Leaders and Beacons - 08-18-2017
ZE Speed Fix - 09-07-2017
ZE Ammo Fix - 08-27-2017
ZE Zombie Skins - 09-19-2017, 04-02-2017, 11-12-2016, 11-01-2016, 07-03-2010
Grenade spam - 08-06-2017
ZE rank and point system/skillbot - 08-06-2017, 08-11-2017, 08-07-2017
ZE (+Zriot) buyzone - 04-20-2017
Transparent players - 04-12-2017, 05-14-2016
ZE: More reserved slots - 03-01-2017
Point system on ZE - 01-24-2017
Rule reminder in chat - 01-25-2017
Disabling fall damage for reg+ or sub+ - 01-02-2017
ZE player inspect and items - 08-17-2017
Tracking Round Wins - 11-11-2016
VIP escort - 03-19-2010
TTT
TTT Karma - 02-04-2018, 08-18-2017, 07-07-2017, 12-23-2016, 05-01-2017, 06-09-2017, 04-23-2017, 07-16-2017, 02-12-2017, 12-18-2016, 10-21-2016,
Karma rewards - 02-03-2018, 10-21-2016
Longer map cooldown - 08-16-2017
Traitor/detective menu - 01-11-2018, 07-02-2017, 06-17-2017, 05-04-2017, 03-18-2017, 03-11-2017, 02-26-2017, 02-14-2017, 01-13-2017, 11-16-2016, 11-08-2016, 11-08-2016, 10-04-2016, 02-08-2016, 03-14-2016, 07-02-2016, 11-07-2016
Mute dead chat - 04-17-2017
Karma as automated ban - 02-12-2017
T room damage - 11-25-2016
Find out who the Traitor Killed - 11-11-2016
Radar issues - 09-28-2016, 08-15-2016
Traitor ring glitch - 06-20-2017, 10-19-2016, 09-24-2016
New T Side Models - 10-14-2017
Add M4A1-S to detective menu - 11-09-2017
Show tased innocents on scoreboard - 11-10-2017
Weeb mode activated - 12-20-2017
Mass RDM Protection - 01-04-2018
Innocent !menu - 02-03-2018, 02-08-2017, 10-01-2016
!Explode on TTT - 01-18-2018
TTT FAQ Suggestions - 02-03-2018
TTT Knife Fight Plugin - 02-23-2018
JB
Dead Player Mute - 08-23-2017, 05-29-2017, 07-11-2017, 03-28-2017
CT Switch - 08-26-2017
Player Slots on JB - 08-03-2017, 08-15-2017, 01-01-2017, 05-29-2011
CT playtime requirements - 06-24-2017, 06-05-2017
CT spam - 10-09-2016
Freeday - 07-19-2017, 12-18-2016, 04-25-2016, 02-27-2017, 09-27-2017, 09-21-2017, 04-19-2016, 01-21-2010, 06-25-2011
LR additions - 01-29-2018, 12-09-2017, 06-30-2017, 05-26-2017, 06-07-2017
Ratio - 10-11-2017, 02-08-2017, 11-20-2016, 02-13-2016, 10-31-2015, 06-25-2011, 09-12-2010
Longer rounds - 06-25-2017
Gun drop on suicide - 04-17-2017
Remove collision - 06-09-2017, 01-16-2017
T's spawn in VIP (razor) - 04-25-2017
Jailbreak gangs - 04-10-2017
Jailbreak Throwing Knifes - 02-14-2017
Jailbreak specific skins for better gun concealing - 02-15-2017
New skins CT/T - 09-24-2016
Map sided death games added in kill feed by person activating death game - 02-12-2017
Wardays - 01-28-2017
Warden - 01-25-2017, 01-04-2017, 01-10-2014, 05-22-2013
CT time restrictions - 03-15-2017, 12-25-2016, 11-15-2016, 07-20-2009
No freedays in small spaces -07-18-2017, 10-15-2017
Spamming weapon skins - 10-14-2017
Throwing Knife - 02-13-2017
KOS area signs - 11-10-2017
Freeday or Slay - 12-13-2017
Deathgames list - 12-31-2017
JB Ranking System/Rewards - 01-12-2018, 08-02-2013
MG
Warmcup health - 08-27-2017
MG third-person - 01-12-2018
AWP submarine quick switching - 02-06-2018
Scrim
Scrim leaderboard - 03-26-2017
Tournament - 10-17-2014, 07-04-2015
Auto-Mute on Scrim - 10-25-2017
Suicide on Scrim - 11-1-2017
Teamkill - 11-1-2017
1v1
1v1 Dueling Plugin - 03-14-2017