Bold style applied to your texts.

	guiText.fontStyle = FontStyle.Bold;

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        guiText.fontStyle = FontStyle.Bold;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		guiText.fontStyle = FontStyle.Bold