Nasus Runes explained
There's one set of runes for Nasus on patch
11.19
that is the clear favorite for LoL players and pros alike. The best Nasus Runes on the position 
Top are Resolve as the primary path and
Inspiration as the secondary path with a pick rate of 40%. Besides runes you should take a look on Nasus Build and if you are interested in pro matches take a look at Nasus Probuilds. If you want to discuss
Nasus then you should visit the champion subreddit.
Primary path on Nasus
Resolve empowers the survivability of Nasus and increases the tankiness. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Grasp of the Undying is the best keystone rune to run on
Nasus. This keystone rune gives Nasus alot of sustain and helps to force your opposing champion out of the lane. This is usually followed up by taking
Demolish,
Second Wind and
Unflinching.
Demolish increases your pressure on the enemy turrets. This rune will help you to punish bad roams or backtimings of your lane opponent.
Second Wind powers up your sustainablity in lane by healing after taking damage from an enemy champion.
Unflinching inceases Nasus tenacity based on your missing health.
Secondary path on Nasus
When it comes to your secondary path, most
Nasus players prefer to go with
Inspiration.
Inspiration opens creative opportunities on Nasus troughout the match. On the
Inspiration path, the best runes for Nasus are
Approach Velocity and
Biscuit Delivery.
Nasus gains bonus movement speed by
Approach Velocity, while moving toward enemy champions that are immobilized or slowed. This rune is perfect to follow up engages by your teammates.
Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes.