Shishio said:
What would you suggest for a good infantry unit?
If you are playing Gekokujo 3.1 then it´s Elite Spearmen. They are cheaper to recruit than Samurai and in a cohesive formation they perform admirably. They are also easy to replace. You are better off using Samurai for Gunners/Archers and Cavalry. I usually have 70 Samurai performing those roles (50 + 20).
However, if you are looking to "solo" your way through towns and castles alike, then I recommend you get Hatamoto Guards and/or Elite Naginata Monks which are basically the highest infantry tiers within the game. Monks hit harder than Hatamoto, but their lack of helmets makes them easy prey to even low tier skirmishers.