>>8845560If it's not about being an outright surprise ask her if she knows of the Spartan Collection figures (reviews for all 8 are on youtube).
Master Chief should be a solid purchase, but try to find it in a physical store where Jerome, Gungnir and Emile are, as that should mean it's a wave/series 2 Master Chief with improvements made over the wave/series 1 version.
The box may also say which wave/series it's from. Kat is also in wave/series 1 and is a female character (if your gf would feel any certain affinity due to the gender).
At this point you probably see it's important to get an idea of what characters/armors she likes. But if it's not a surprise and Covid lockdown isn't strict in your area, you can just make an outing of it and let her pick from a location you have made sure has Halo figures.
There's also World of Halo. It's a more space efficient size of figures, with most having reviews on youtube. It's in the middle of going from series 1 to series 2 so finding either in store can be tricky. It does have vehicles like the Warthog and Ghost, as well as multi-packs instead of just single figures.
Last but not least are the Mega Bloks/Construx figures. Smaller, customizable armor parts, way more space efficient, also has vehicles (even larger ones like tanks and aircraft) or sets with structures and scenery. You have to build them like Lego which could be a fun time together? but anyway their figures are still far more articulated and detailed than Lego minifigures and also come alone or in multi-packs.
Those are all the lines currently being produced with options that are of the lower end price. Older Mega Bloks/Construx can be pretty high price, same with older Mattel Halo figures (good luck getting the Locus figure made by them for retail price), even older McFarlane figures and then the ancient Joyride figures.
Now get googling or whatever search engine you use. Good hunting.