Warner Brothers' official Looney Tunes site used to feature very weak, newly-produced Flash cartoons. Recently they've wised up and started offering actual classic cartoons as web content, including some that aren't on DVD yet (but which might be on the next Looney Tunes Golden Collection later this year). Here's the page with all the cartoons they have available for viewing.
One semi-obscure cartoon I'd like to call your attention to is "It's Hummer Time."
This is a 1950 cartoon directed by Robert McKimson, one of many odd and quirky one-shot cartoons he made in the early '50s. The central character is a mischievous hummingbird, sort of a singing version of the early, vicious Tweety Bird -- there's even a Tweety reference in the cartoon -- who is pursued by a cat. The hummingbird keeps turning the tables on him and getting him in trouble with a big grey dog. A standard premise, but the twist is that every time the cat gets in trouble, the dog punishes him with an elaborate, sadistic penalty, despite the cat's pleas for mercy: "Not the Thinker! No, please! NOT THE THINKER!!!" Like many of McKimson's cartoons from this period, it undercuts the stereotype of McKimson as a "square" or unimaginative director; it's got great, off-kilter gags, imaginatively staged with good use of perspective (characters running from background to foreground and back again). Great animation, too, from the likes of Bill Melendez and Rod Scribner.
The cartoon's soundtrack features a whole bunch of popular songs that were regular staples of Carl Stalling's scores: "I'm Looking Over a Four Leaf Clover," "By a Waterfall," "Ain't We Got Fun?," "The Teddy Bear's Picnic," "Baby Face." But the biggest presence on the soundtrack is Raymond Scott's "Powerhouse," which underscores every "penalty" scene.