Complete metric wrench set, 3/8 metric socket set (long and short) with a handful of 1/2 drive sockets thrown in, a few pair of small vicegrip, plier assortment, screwdriver assortment, a few short gear wrench's, misc electrical repair stuff and my volt meter has a temp probe. 1.5 pound sledge with a short metal handle. A few specialty suspension tools. Most importantly is an 8 inch pipe wrench. I'm sure I forgot a few.
Colby valve stems, a few tubes of aluma seal, a tube of block/head sealant, tire plug kit.
If you have custom rims make sure you can take off the lug nuts. I have what's called a
flip socket. The picture is so you have an idea. Mine are snap on. You need a 3" extension for the middle. Thin wall impact rated. Most aftermarket rims, the opening where the lug nut goes through is smaller than stock. Tire wrench wont fit.
I know I have more then that but there's the bulk of it.
When I do my maintenance, I use my trucks tool kit only, including the jack. You find out quickly what your missing. I also carry a small bolt collection. Make sure your tools go as big as the biggest thing you may need to remove. This is what my 1/2 sockets are for.