I don't know about you, but I find it extremely annoying having to visit mojang.com and having to find the new server .jar and then turn it into a .exe for my computer. So here are some helpful links, all in one place.

Vanilla
1.8.4
.jar: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.4/minecraft_server.1.8.4.jar
.exe: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.4/minecraft_server.1.8.4.exe
1.8.2 pre-1
.jar: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.2-pre1/minecraft_server.1.8.2-pre1.jar
.exe: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.2-pre1/minecraft_server.1.8.2-pre1.exe
1.8.1 (release)
.jar: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.1/minecraft_server.1.8.1.jar
.exe: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.1/minecraft_server.1.8.1.exe

Spigot
1.8.3
https://hub.spigotmc.org/jenkins/job/BuildTools/
1.8
Windows: http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
http://msysgit.github.io/
https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar

Bukkit
Bukkit has recently had its downloads taken down.

All these links/downloads are from their original sources and all files downloaded from the above are legally public.