Generally speaking, beers that are simply styled as pale ales are lower in strength and less bitter than beer labeled as India Pale Ale. I am sure you could have easily guessed that double or Imperial IPAs are bigger beers than an IPA.
Here are a few thirst-quenching pale ales recommended by the distinguished taste panel at Beers to You:
Blue Heron, by Mendocino Brewing Co.: The lightest of the pack with a citrus hop finish.
Southern Hemisphere Harvest Ale, by Sierra Nevada Brewing: The most bitter of the pack, using a generous dose of freshly harvested hops from New Zealand.
Orval Trappist Ale: The Trappist beer with an identity crisis. The beer takes many cues from traditional English pale ale, but this beer quickly asserts its Belgian heritage with its spicy and dry finish. The spiciness and carbonation are derived from the fermentation process and bottle conditioning methods that are similar to but predate methods used in making champagne.
Bridge Brew Works Pale Ale: A great beer from the boys in Fayetteville. This beer is only available on tap. The beer is very drinkable with a refreshing hop finish.
Rogue Juniper Pale Ale: A moderately bitter brew in which the bitterness is supported by the herbal complexity of juniper berries (also used in making gin) added during the brewing and conditioning process.
Widmer X114 IPA: A medium-bitterness IPA that uses a few special varieties of hops from the Pacific Northwest. The hops impart a distinct hint of orange along with floral and herbal notes. One of us tasted basil, and I tasted rosemary. Go figure.
For more on the craft of beer, see Rich Ireland's Beers to You blog at thegazz.com.