I can confirm this is not fixed on 4.3.4f1 adb.exe launched when play mode entered for the first time. Prevents unity from closing until adb.exe terminated. Running Win 8.1 Pro

I can confirm this is not fixed on 4.3.4f1 adb.exe launched when play mode entered for the first time. Prevents unity from closing until adb.exe terminated. Running Win 8.1 Pro

Same issue reported a few times, and contrary to the 'fixed' issue status's, remains unfixed as of 4.3.4f1

Still getting this in 4.3.4f1. I created a new project and didn't import any assets. I created 1 C# script that called Debug.Log. I attached that script to the 'Main Camera' object ran the game in the editor and then stopped it. After that when I tried to exit it didn't hang. If I just created the empty project and didn't play it it didn't hang.

About half the time when running adb kill-server to stop adb unity crashes and the rest of the time it appears to exit cleanly.

Same as 3DART.ES
Unity freezed at close, terminate adb and then Unity exit.

Still have this problem too.
Unity Free 4.3.3f1
Win7 x64 SP1

Definitely not fixed in 4.3.3f1. Only happens when (for me) when I have loaded a scene sometime during the process' (Unity.exe) lifetime. "Me loading" also includes scenes loaded automatically by Unity at startup.

Still happens: 4.3.3 - can we have it re-opened?

Here's a workaround.

Somewhere in your assets folder, make a folder called Editor. Make a new C# script in there, and replace the contents with the script below. Afterward, you'll have two new menu options:
1) Tools/Kill Android Proc
2) File/Exit Cleanly

Kill android proc kills ADB (use this before changing scenes)
Exit Cleanly kills ADB, asks to save scene, saves assets then quits.

using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Diagnostics;

public class CloseAndroidProc : MonoBehaviour
{
static void KillAndroidProc()
{
ProcessStartInfo psi = new ProcessStartInfo
{
FileName = @"C:\Windows\System32\taskkill.exe",
Arguments = "-f -im adb.exe"
};
Process.Start(psi);
}

[MenuItem("Tools/Kill Android Proc", false, 1000)]
public static void MenuToolsKillAndroid()
{
KillAndroidProc();
}

[MenuItem("File/Exit Cleanly", false, 1000)]
public static void MenuQuitCleanly()
{
KillAndroidProc();

EditorApplication.SaveCurrentSceneIfUserWantsTo();
EditorApplication.SaveAssets();
EditorApplication.Exit(0);
}

}

Definitely not fixed for Unity 4.3.3f1 and Windows 7 pro. If you use a batch file as described here it fixes the problem: http://answers.unity3d.com/questions/582789/unity-freezes-on-quit-43.html