Apart from dark matter, and Energy (if you take into account the matter / energy equivalency behind nuclear bombs as reconciled by Einstein's E=mc²) Then baryonic (normal) matter itself has many little known forms beyond antimatter and negative matter. It's quite fascinating.
It's difficult to understand matter fully so in that spirit this post seeks merely to describe aspects of its known range. The chart below shows us the mystery of the unknown matter and energy making up about 96% of the universe, which this post doesn't even go into.
Wikipedia states:
"A phase is a form of matter that has a relatively uniform chemical composition and physical properties (such as density, specific heat, refractive index, and so forth). These phases include the three familiar ones (solids, liquids, and gases), as well as more exotic states of matter (such as plasmas, superfluids, supersolids, Bose–Einstein condensates, ...). A fluid may be a liquid, gas or plasma. There are also paramagnetic and ferromagnetic phases of magnetic materials. As conditions change, matter may change from one phase into another. These phenomena are called phase transitions, and are studied in the field of thermodynamics. In nanomaterials, the vastly increased ratio of surface area to volume results in matter that can exhibit properties entirely different from those of bulk material, and not well described by any bulk phase (see nanomaterials for more details)."
But that's by no means the end of the story. The video below covers some of the more bizarre states of matter we never hear about, including 18 different kinds of water ice, time crystals, superfluids and frictionless matter, as well as the weirdness in states of matter we find in nature's densest matter environment, neutron stars (It's a surprisingly little known fact that black holes contain no matter, they have become singularities rather than super dense matter, they owe their extreme gravity to super warping of spacetime)