Normal mode
Hardcore | Egg armour - There's no natural health regeneration and people will die quickly that's why you need armour quickly to give you a huge advantage in fights!
Normal | Healer - Golden apples are seriously underated in normal mode, especially when your opponents don't have any! The resistance and regeneration give you a huge advantage before going into a fight!
Over powered | Money bags - Money bags is a personal favourite of mine and is a good kit for every mode. The reason it is so good for OP is that everything is cheap, including obsidian meaning people get very good protection of their eggs quickly. When you spawn and are first to the iron generator you have 25 iron (+10 money bags) Just enough for basic gear; armour, weapon, food, pick axe and blocks.
Speed mode
There are a lot of good kits for speed mode and 'the best one' often depends on your playing style.
Hardcore | Golden shell - Golden armour is quite a bit better than leather giving you an instant advantage over players before the game has even started. Also it is time consuming and expensive to buy armour, meaning teams have more time to protect their eggs which you don't want in speed mode!
Normal | Golden shell - Gives you a huge advantage in PvP, allows for quick preparation and allows you to take eggs quickly!
Over powered | Egg legs - In overpowered mode protection is incredibly cheap meaning games will almost definitely last a long time unless you get to an egg ASAP! Egg legs gives you two speed two potions allowing you to get around the map quickly and make the game a lot quicker and more enjoyable!
Please like if you agree as it really helps me out!