As a lover of the SIG since... since I first learned of handgun differences, they're all fine.
The P220 - full sized .45 (4 1/2 inch or so barrel)
P220 match has a 5" barrel, P220 Carry has under 7" length, full grip, P220 Compact is the P245 with a better backstrap.
The P225 - the 7 inch long, 9mm version of the P220 (discontinued, but a flood of used P6's are coming in from CDNN)
The P226 - full sized 9mm, .40 and .357 - the almost 8 inch long version.
The P228 - dedicated 9mm, 7 inches long, 13 rounds (and appropriately shorter grip)
The P229 - mid-sized 9mm, .40 and .357 - the 7 inch long version, minus 2 capacity from the 226.
The P245 - .45 ACP, in P225 dimensions, more or less.
The P239 - a SIG P230-sized 9mm, .40, or .357 with single stack mag and quite slim and comfy.
The P230 - the Walther PP or PPK with better ergonomics and decocking mechanism.
Oldest favorites are the big SIGs, the P220 and the P226. To show how old and oddball I am, my favorite P220 is the .38 Super. Best stand-in for that oddballness is the P226 in .357 Sig, with the bonus cheetoh that the .357 SIG '226 has four more shots.