Whole-Fat-Pixel UI for NGUI (Unity). I grabbed this useful script for Unity UI pixel placement from here: http://pastebin.com/EaZPHQPx

UIResizer.cs

using UnityEngine;

[ExecuteInEditMode, RequireComponent(typeof(UIRoot))]
public class UIResizer : MonoBehaviour {
	
	public enum GizmoRegion {
		Border,
		Center,
		Edges,
		All,
	};
	
	public Camera uiCamera;
	public int desiredPixelWidth = 160;
	public int desiredPixelHeight = 120;
	public bool forceUpdate = false;
	public int pixelHeight = 0;
	private int lastPixelWidth = 0;
	private int lastPixelHeight = 0;
	private int lastManualHeight = 0;
	private float desiredScreenRatio;
	
	public GizmoRegion gizmoRegion = GizmoRegion.Border;
	
	void OnEnable() {
		if(uiCamera == null) {
			uiCamera = GetComponentInChildren<Camera>();
		}
	}
	
	void Update() {
		if(desiredPixelWidth <= 0) {
			desiredPixelWidth = 1;
		}
		if(desiredPixelHeight <= 0) {
			desiredPixelHeight = 1;
		}
		
		UIRoot root = GetComponent<UIRoot>();
		if(desiredPixelWidth != lastPixelWidth ||
			desiredPixelHeight != lastPixelHeight ||
			lastManualHeight != root.manualHeight ||
			forceUpdate) {
			forceUpdate = false;
			lastPixelWidth = desiredPixelWidth;
			lastPixelHeight = desiredPixelHeight;
			lastManualHeight = root.manualHeight;
			
			desiredScreenRatio = (float)desiredPixelWidth / (float)desiredPixelHeight;
			
			// Find the largest scale that fits in the height.
			int pixelScale = 1;
			while(desiredPixelWidth * (pixelScale + 1) <= Screen.width &&
				desiredPixelHeight * (pixelScale + 1) <= Screen.height) {
				pixelScale++;
			}
			
			// Set the UIRoot's manual scale to that!
			root.minimumHeight = 1;
			root.maximumHeight = 4096;
			root.manualHeight = Screen.height / pixelScale;
			root.automatic = false;
			lastManualHeight = root.manualHeight;
			
			root.SendMessage("Update");
			pixelHeight = pixelScale;
		}
	}
	
#if UNITY_EDITOR
	void OnDrawGizmos() {
		float aspectRatio = uiCamera.aspect;
		
		float screenTop = transform.localScale.y * lastManualHeight / 2;
		float screenBottom = -transform.localScale.y * lastManualHeight / 2;
		float screenLeft = -transform.localScale.x * lastManualHeight / 2 * aspectRatio;
		float screenRight = transform.localScale.x * lastManualHeight / 2 * aspectRatio;
		
		float minAspectTop = transform.localScale.y * desiredPixelHeight / 2;
		float minAspectBottom = -transform.localScale.y * desiredPixelHeight / 2;
		float minAspectLeft = -transform.localScale.x * desiredPixelHeight / 2 * desiredScreenRatio;
		float minAspectRight = transform.localScale.x * desiredPixelHeight / 2 * desiredScreenRatio;
		
		// Center cross.
		Gizmos.color = new Color(1f, 1f, 1f, 0.2f);
		Gizmos.DrawLine(new Vector3(0f, screenTop, 0f) + transform.localPosition, new Vector3(0f, screenBottom, 0f) + transform.localPosition);
		Gizmos.DrawLine(new Vector3(screenLeft, 0f, 0f) + transform.localPosition, new Vector3(screenRight, 0f, 0f) + transform.localPosition);
		
		// Screen outline.
		Gizmos.color = new Color(1f, 1f, 1f, 0.6f);
		Gizmos.DrawWireCube(transform.localPosition, new Vector3(screenRight - screenLeft, screenTop - screenBottom, 0f));
		
		if(gizmoRegion == GizmoRegion.Center || gizmoRegion == GizmoRegion.All) {
			float edgeSize;
			float edgeCenter;
			
			// Left and right danger zones.
			Gizmos.color = new Color(1f, 0f, 0f, 0.2f);
			edgeSize = minAspectLeft - screenLeft;
			if(edgeSize < 0f) {
				Gizmos.color = new Color(0f, 0.5f, 0f, 0.2f);
				edgeSize = Mathf.Abs(edgeSize);
			}
			edgeCenter = (minAspectLeft + screenLeft) / 2;
			Gizmos.DrawCube(new Vector3(edgeCenter, 0f, 0f) + transform.localPosition, new Vector3(edgeSize, screenTop - screenBottom, 0f));
			edgeCenter = (minAspectRight + screenRight) / 2;
			Gizmos.DrawCube(new Vector3(edgeCenter, 0f, 0f) + transform.localPosition, new Vector3(edgeSize, screenTop - screenBottom, 0f));
			
			// Top and bottom danger zones.
			Gizmos.color = new Color(1f, 0f, 0f, 0.2f);
			edgeSize = screenTop - minAspectTop;
			if(edgeSize < 0f) {
				Gizmos.color = new Color(0f, 0.5f, 0f, 0.2f);
				edgeSize = Mathf.Abs(edgeSize);
			}
			edgeCenter = (minAspectTop + screenTop) / 2;
			Gizmos.DrawCube(new Vector3(0f, edgeCenter, 0f) + transform.localPosition, new Vector3(screenRight - screenLeft, edgeSize, 0f));
			edgeCenter = (minAspectBottom + screenBottom) / 2;
			Gizmos.DrawCube(new Vector3(0f, edgeCenter, 0f) + transform.localPosition, new Vector3(screenRight - screenLeft, edgeSize, 0f));
			
			Gizmos.color = new Color(1f, 0f, 0f, 0.8f);
			Gizmos.DrawWireCube(transform.localPosition, new Vector3(minAspectRight - minAspectLeft, minAspectTop - minAspectBottom, 0f));
		}
		if(gizmoRegion == GizmoRegion.Edges || gizmoRegion == GizmoRegion.All) {
			float edgeSize;
			//float edgeCenter;
			
			// Left and right safe zones.
			Gizmos.color = new Color(0f, 1f, 1f, 0.8f);
			edgeSize = -minAspectLeft;
			if(minAspectLeft < screenLeft) {
				Gizmos.color = new Color(1f, 1f, 0f, 0.8f);
			}
			/*edgeCenter = screenLeft - minAspectLeft / 2;
			Gizmos.DrawCube(new Vector3(edgeCenter, 0f, 0f), new Vector3(edgeSize, screenTop - screenBottom, 0f));
			edgeCenter = screenRight - minAspectRight / 2;
			Gizmos.DrawCube(new Vector3(edgeCenter, 0f, 0f), new Vector3(edgeSize, screenTop - screenBottom, 0f));*/
			Gizmos.DrawLine(new Vector3(screenLeft + edgeSize, screenTop, 0f) + transform.localPosition,
				new Vector3(screenLeft + edgeSize, screenBottom, 0f) + transform.localPosition);
			Gizmos.DrawLine(new Vector3(screenRight - edgeSize, screenTop, 0f) + transform.localPosition,
				new Vector3(screenRight - edgeSize, screenBottom, 0f) + transform.localPosition);
			
			// Top and bottom safe zones.
			Gizmos.color = new Color(0f, 1f, 1f, 0.8f);
			edgeSize = minAspectTop;
			if(screenTop < minAspectTop) {
				Gizmos.color = new Color(1f, 1f, 0f, 0.8f);
			}
			/*edgeCenter = screenTop - minAspectTop / 2;
			Gizmos.DrawCube(new Vector3(0f, edgeCenter, 0f), new Vector3(screenRight - screenLeft, edgeSize, 0f));
			edgeCenter = screenBottom - minAspectBottom / 2;
			Gizmos.DrawCube(new Vector3(0f, edgeCenter, 0f), new Vector3(screenRight - screenLeft, edgeSize, 0f));*/
			Gizmos.DrawLine(new Vector3(screenLeft, screenTop - edgeSize, 0f) + transform.localPosition,
				new Vector3(screenRight, screenTop - edgeSize, 0f) + transform.localPosition);
			Gizmos.DrawLine(new Vector3(screenLeft, screenBottom + edgeSize, 0f) + transform.localPosition,
				new Vector3(screenRight, screenBottom + edgeSize, 0f) + transform.localPosition);
		}
	}
#endif
}