Minecraft

I've not been particularly active lately.

Visited some servers but didn't find the people that asked me to join them online.

minecraft.dtrtech.com - 1.5_01

Whitelist- email to join.
Became a ghost town soon as 1.6_01 rolled around. Relatively new map. Friendly people (when they are around).
This server replaces newcanada.dtrtech.com . Few of the players returned to this and an update to 1.7.2 seems unlikely.

Kfperin's SMP Server [KSMP]

Whitelist- in game chat to join.
Incremental backups every half-hour. Good moderators. Large, active and friendly player base. Forums. Steam group. While waiting for modifications to be updated a temporary map is used. mc1.xegup.com
This was one of the first servers I visited when I got Minecraft, and I have maintained a presence here, though the terrible performance of my machine limits how much I can enjoy the built up areas.
I point to this as an example of Minecraft hosting/administration done right.

minelife.tk

Blacklist.
Seems to suffer from under moderation. Tried joining their forums, but didn't even get a rejection mail. Player base appears to be very active and growing.

Others

Been asked to join many other servers. Will visit occasionally, but I do not have the time to be active on more than two.