Someone asked me just today about my biases and preferences, and I said that while I usually gravitate toward the lighter bass and the less-bright high end, I think the L1 is so good that with a little bass reduction, I can enjoy it for hours at a time. I've had several good finds below the $300 USD mark, so here's my brief summary of those:
Philips L1 - heavy bass becomes perfect after a bit of EQ, mids and highs excellent, I think these can provide very long term enjoyment to people who like heavy bass, or, if they are willing to EQ, a still-strong bass with great mids and highs. Well worth the money, highly recommended.
Shure 940 - lighter than average bass but still very good, excellent mids, and slightly bright below 10 khz. This will fit a much narrower range of users than the L1, but for anyone who prefers the so-called "neutral" signature, these are a tremendous bargain at $300. Not good with the average low-cost solid state amp.
Beyer DT-1350 - with the new more comfy headband, a large emphasis and hollow sound around 440 to 500 hz. Really needs EQ to bring that down some. Even then, the earpad seal is critical, and walking outdoors in cool weather it takes quite a while for the earpads to adjust and seal their best.
B&W P5 - a good smooth almost-neutral sound, but soft in the bass and highs. Not the highest fidelity in my opinion.
German Maestro 8.35D - before the L1 arrived, the best sound below $300 that I've heard. Good strong bass that's not bumped up or boomy - near perfect. Decent mids and highs.
VModa M-80 - probably the best sound below $250, only complaint is rolled off highs, which fixes up pretty well with some EQ. Both this and the DT-1350 suffer some from small-earcup congestion.
Phiaton MS-400 - very bassy, does not correct as well as the L1, but still not bad. Overall a very pleasant, almost liquid-like sound that's very nice for portable use. Not the highest fidelity. Of the MS-400, M-80, P5, and DT-1350, the DT-1350 is probably the most hifi if you can get the balance EQ'd or a better earpad seal.