Well, let's see. How much do you want to spend? Do you have a stationary amp, and a good source? Do you want open or closed headphones?
Yes, the Senns have the closest sound signature to your Shures. The HD650 will probably give you what you want provided that it is well amped. If it isn't well amped it can actually fall behind the E500 in sound quality, but in a good rig it will be significantly better. It will have a bit more presence in the highs but it will also have substantially more extension in the highs as well. The HD650 treble is a bit recessed but very extended, and is IMO one of the best trebles I've heard in a dynamic headphone. The mids can range from a bit dry to lovely and lush, depending on the rest of your system. The bass can be bloated and overpowering or tight, deep, and impactful, once again depending on your system, and more precisely on how much power your amp can deliver. With the HD650, more power = more betterer
Grados will be quite different. I don't have too much experience past the SR-60, but so far I've heard a lot more treble energy, more forward sound signature with a smaller soundstage, but good air/instrument separation, and very good impact. I'd say they're closer to the Etymotic sound signature than they are to the Shure sound, but with substantially more kicking bass and fuller midrange.
Vintage AKG's can give you a sound that is Shure-like in some respects, but with a lot more presence and crispness in the highs. The K340 does have a very full midrange, a tight and punchy bass in the bass-light versions, and quite a bit more presence/extension in the highs. Like balanced-armature canalphones it is a very quick headphone, thanks to its electret tweeter. The difficulty with it is a) driving it right, and b) finding a good-sounding pair. Different pairs really do sound differently, and you never know what you're going to get.
Stax would be a good option if you're starting out in full-size cans, though electrostatics get really expensive really quick, and absolutely, positively require top-notch sources to sound good. I think the Omega 2 would be more or less exactly what you're looking for, but it will cost you a lot, and you really shouldn't drive it with Stax amps, but rather opt for a KGSS, Blue Hawaii if you can get someone to custom-build one for you, Woo GES maybe, or an SRD-7 Pro transformer box with a beefy speaker amp. Stax amps don't have the juice to wake up the O2. Lower-end Stax models have a decidedly un-Shure-like sound signature, but listen to them, maybe you will like them. They have less presence in the mids and a lot more presence in the highs, with a somewhat electric midrange coloration with emphasized upper midrange (rather than the warm, lush, somewhat throaty midrange of the Shures which stress lower midrange a lot). The 2050 system is a very good bargain and should be a good teaser for the 'stat world - but even it needs a very good source.
But, that's just a general summary. We do need to know more about budget and the rest of your system.