I also like Galaxy Fight. Reasons:
- Can be considered a prequel to WW7 and it has an unusual, hence interesting roster.
- Similar to Art of Fighting 3, Galaxy Fight offers a unique gameplay, in this case based on dashing. Once you grasp it, it gets quite addictive.
- It's a SUNSOFT game and stands out for that reason alone, comes with a quality soundtrack, too.
On topic: I'd go with...
Pulstar - another great R-Type variation on the Neo
Panic Bomber - excellent, yet quite difficult puzzler with a top soundtrack
Galaxy Fight - see above
Savage Reign - the best use of the SNK trademarked 'two plane' concept in my opinion
Samurai Spirits III - obvious choice, the last no-compromise part of the series, tricky ai for single player
I tried to like Gowcaizer, but at this time: no dice. Kabuki Klash is good, but it's not as crazy, as it wants to be and has a weak roster due to its Far East of Eden presets.