These are some of the methods:
"Adams" - predictor-corrector Adams method with orders 1 through 12
"BDF" - Gear implicit backward differentiation formulas with orders 1 through 5
"ExplicitRungeKutta" - adaptive embedded pairs of 2(1) through 9(8) Runge-Kutta methods
"ImplicitRungeKutta" - families of arbitrary-order implicit Runge-Kutta methods
"SymplecticPartitionedRungeKutta" - interleaved Runge-Kutta methods for separable Hamiltonian systems
"MethodOfLines" - method of lines for solution of PDEs
"Extrapolation" - (Gragg-)Bulirsch-Stoer extrapolation method, with possible submethods
"ExplicitEuler" - forward Euler method
"ExplicitMidpoint" - midpoint rule method
"ExplicitModifiedMidpoint" - midpoint rule method with Gragg smoothing
"LinearlyImplicitEuler" - linearly implicit Euler method
"LinearlyImplicitMidpoint" - linearly implicit midpoint rule method
"LinearlyImplicitModifiedMidpoint" - linearly implicit Bader-smoothed midpoint rule method
"DoubleStep" - "baby" version of "Extrapolation"
"LocallyExact" - numerical approximation to locally exact symbolic solution
"StiffnessSwitching" - allows switching between nonstiff and stiff methods in the middle of the integration
"Projection" - invariant-preserving method
"OrthogonalProjection" - method that preserves orthonormality of solutions
"IDA" - general purpose solver for the initial value problem for systems of differential-algebraic equations (DAEs)
"Shooting" - shooting method for BVPs
"Chasing" - Gelfand-Lokutsiyevskii chasing method for BVPs
"EventLocator" - event location for detecting discontinuities, periods, etc.