I better be diplomatic about this and suggest that DIY gifts for men
needn't be any different than those which would be suitable for all the
ladies amongst us (and even "non-ladies"!) Speaking as a serious male
DIYer, I would like a cordless drill with two lithium batteries. The
advantage of this battery technology is that the batteries don't lose
their charge as quickly, and the drill is always ready for use.
A mitre(miter) saw is useful for making square cuts on timber, dado rail etc. An 8inch version is fine.
Jigsaws are useful for making curved and straight cuts in sheet timber. Go for one with variable speed on the trigger.
Angle grinders are useful for cutting metal and masonry.
A socket wrench set or ratchet wrenches(spanners) are always handy for tightening and undoing nuts and bolts.
Personally
I would prefer to buy my own hand tools. While power tools are somewhat
similar, the shape and size of hand tools are such that it is better to
try them in your hand before buying. I mean how would a woman feel if
their partner bought them shoes?