Crucial has had its share of firmware bugs. As the m4 was one of the first SATAIII drives on the market, it's had plenty of time to work out the kinks, and they seem reliable enough at this time. It's not that Intel or Samsung haven't had any bad firmware bugs, either (Intel's 8MB issue and a preproduction issue with the new Samsung 840 Pro).
^^I'm not trying to discourage anybody from any of the SSDs mentioned above, since they are all quite good.
Anyways, if you are looking for the best-performing consumer SSD on the market, the Samsung 840 Pro is it. Overall, it's about 20% faster than the last generation drives (e.g. Samsung 830, Intel 520, etc.). Its high performance does come at a price premium, but it is the best performing drive.
If you are feeling particularly brave, The OCZ Vector is a new drive from OCZ with similar performance to the 840 Pro. OCZ has had A LOT of turmoil in the past few years with reliability concerns and bad management (the company's founder and CEO was booted, and the company was investigated for "creative accounting"). The new drive does seem quite solid, however.
If you were looking for a slightly cheaper drive, the Samsung 840 (non-pro version), Samsung 830, Intel 520, and Intel 330/335 series are still viable. Regarding the Samsung 840, the difference between it and the Pro version is that the vanilla uses TLC memory. This means each NAND cell holds 3 bits of data (instead of the more common 2-bit MLC). This makes it cheaper to produce at the expense of some performance and durability. The performance is about the same as the 830, and Samsung has said that durability shouldn't be a problem for typical client workloads.
Honorable mention goes to an enterprise drive Intel just released, the DC S3700. The performance is a little lower than the Samsung 840 Pro, but they really targeted performance consistency. The drive can be tortured in any way possible (filling it up with random data, no TRIM, hammering at high queue depths for extended periods of time) and the drive just keeps on chugging along. It is an enterprise drive so it's very resilient and expensive, so probably not what any consumer is looking for, but it is just awesome
So, to sum up, if you're looking for the best of the best (client workloads):
Samsung 840 Pro. OCZ Vector if you are feeling brave.
Good bang for your buck:
Samsung 840 (vanilla version), Samsung 830 (slowly going out of stock), Intel 520/330/335 (520 is more durable, not sure if this will be needed on client workloads. 335 uses smaller NAND, should be a little cheaper than 330 at the theoretical loss of some durability)