I'd suggest RISC-V, not only because it is inevitable and rapidly growing the strongest ecosystem, or because the MIPS ISA is no more (company who owns it switc

I'd suggest RISC-V, not only because it is inevitable and rapidly growing the strongest ecosystem, or because the MIPS ISA is no more (company who owns it switched to RISC-V) but because it is free of microarchitecture spilling into ISA, which MIPS is guilty of. From a programmer POV, RISC-V is not unlike MIPS, but much easier.