Which processor-specific option is best for my processor?

SSE4.2
Intel® Core™ i7 ProcessorsIntel® Xeon® 55XX series

SSE4.1
Intel® Xeon® 74XX series Quad-Core Intel® Xeon 54XX, 33XX series Dual-Core Intel® Xeon 52XX, 31XX series Intel® Core™ 2 Extreme 9XXX series Intel® Core™ 2 Quad 9XXX series Intel® Core™ 2 Duo 8XXX series Intel® Core™ 2 Duo E7200

SSSE3
Quad-Core Intel® Xeon® 73XX, 53XX, 32XX series Dual-Core Intel® Xeon® 72XX, 53XX, 51XX, 30XX series In tel® Core™ 2 Extreme 7XXX, 6XXX series Intel® Core™ 2 Quad 6XXX series Intel® Core™ 2 Duo 7XXX (except E7200), 6XXX, 5XXX, 4XXX series Intel® Core™ 2 Solo 2XXX series Intel® Pentium® dual-core processor E2XXX, T23XX series

SSE3
Dual-Core Intel® Xeon® 70XX, 71XX, 50XX Series Dual-Core Intel® Xeon® processor (ULV and LV) 1.66, 2.0, 2.16 Dual-Core Intel® Xeon® 2.8 Intel® Xeon® processors with SSE3 instruction set support Intel® Core™ Duo Intel® Core™ Solo Intel® Pentium® dual-core processor T21XX, T20XX series Intel® Pentium® processor Extreme Edition Intel® Pentium® D Intel® Pentium® 4 processors with SSE3 instruction set support

SSE2(default)
Intel® Xeon® processors Intel® Pentium® 4 processors Intel® Pentium® M

IA32
Intel® Pentium® III ProcessorIntel® Pentium® II ProcessorIntel® Pentium® Processor