For Scotch, I favor the islay variants over the highlands types. Costco is currently carrying Laphroaig at $30 a bottle, which is a screaming deal. "Like kissing a mermaid that just ate BBQ" is the schtick, and it's an apt description. Very peaty, dark, rich and complex.
For Japanese, I like Iwai Traditions (white label, not the blue label). This is a bit more expensive at about $50 a bottle at most liquor stores. Japanese whiskey lacks consistency (to my palate, at least). There's not really a theme to it as a national class of whiskey, unlike Irish/Scotch/Bourbon/etc. I can't stand Suntori Toki, for instance. Way too sweet, to much corn polish flavor to it (at least as I perceive it).
Have you tried Rye? Bulleit Rye is pretty trustworthy for an unadulterated, straight Rye for a good value. Some Ryes wind up with too much after-flavoring... Pendleton is vanilla-syrupy to me. Templeton is good, too... and Dickle. Neither is too expensive.
Being that everything tastes better at 7000 feet elevation and colder weather, I do most of my really cheap whiskey drinking while camping. Evan Williams, Jim Beam, Jack Daniels. Beam tends to give me a headache that the other two don't. I can't say I've explored the Bourbon world so far.
Irish: I favor Jamison over Bushmills. Probably my favorite Irish I've come across thus far though, is Red Breast. Tullamore Dew is decent for the price.