I'll weigh in on the Lexus IS 300:
I did have one as a loaner car for a week, and I've driven it many times, seen many come into the dealership, and blah blah blah.
The handling is really tight, you can shut off the VSC (traction control), and it handles just like a 3-series. I've driven them back-to-back, and there's no real difference, in my opinion. (Unfortunately, I haven't really done so on a bona-fide racetrack.) The steering has real feeling to it, unlike every other Lexus. The seats are grippy, and there's four doors, with rear seats that aren't a chore for adults to sit in. They all have the 220hp inline-6 motor, and some are available in 5-speed manuals (2002-2005). No paddle shifters on the autos (not until 2006+), although they had that E-shift that rarely anyone used, because the buttons were too small.
A small handful of IS 300s with 16" wheels, cloth interiors, standard seats, and no sunroof are also available. The handling is sluggish on the 16" wheels, although you get far more tire life in return (see below).
The motors are reliable, and easy to maintain. Spark plug replacement's tricky, since the intake and plenum have to be removed to get inside. The one fault is that it is difficult to tune, when wedged inside the IS. There's not much room for a 2JZ-GTE (inline-6 twin-turbo) swap without a lot of modifications, since the engine is crammed into the front end. It's not impossible, but consult an team of experts. There's a lot of other aftermarket stuff for it. If that's not your thing, then it's no big deal.
Known issues: Oxygen sensors if the car was not using 91+ octane; basically, Toyota's Achilles' Heel, except it's generally not much trouble (nor even noticeable) unless two of them go south. Don't spray too much water into the engine bay, or you may get a little water into the engine cover, and into the spark plug chamber. Early 2001-03 models would run afoul of this occasionally from detailers.
The tires aren't cheap on this car, and you will only get 12,000-15,000 from spirited driving. Heavy leadfoots get even less, mostly because the inner edges will go bald much faster than the outer sidewall crowns. Any decent tire for this car (V-rated and above) is directional, so forget about trying to "invert the tires" to gain tire life. It's possible if you're fanatical about it, and you get the right sort of tires, but unless you have the ability to break down tires off their rims every 3000 miles or so, it's not worth the trouble. The camber is not very adjustable, so you can't really tweak it much to prevent this situation; inverting tires only makes it a little harder to center the car at higher speeds. The only solution is getting a sweet deal on tires.
2001 models had a few silly recall issues that have probably all been fixed at the dealer; underbody panels, suspension pieces, a tire recall (see above). The 2001 year also saw a few faulty transmission control units (automatics, of course) that caused rare hiccups between 3rd-4th and 4th-5th gear at highway speeds; some could be "re-flashed" at the dealer, others could not (replacement).
A/C power servo-motors tend to make incessant clicking noises at around 40,000-80,000 miles. It's a 2.2-hour job and a $150.00 part at the dealer, as I recall. Some people live with the noise, others can't stand it. It rarely affects the A/C performance, although a few people had temperature (coldest setting only) or vent issues (stuck in one directional blowing mode) to go with that.
Clutches are not cheap on this car; Lexus recommends a new flywheel, even though most techs disagreed with that practice. So don't take it to the dealer unless you have $2500-3000 for a new clutch. I saw a few clutch issues on the IS, and they were all at around 30,000 miles or so, but they were all young owners as well. The over-35 crowd would have over 100,000 miles on the same clutch, with no problems. Go figure...
Interior trim is a shade less fancy than most Lexuses, but mostly top notch, if cared for. Some surfaces scratch-up easily, like switch bezels, since Toyota experimented with painted surfaces for a "high-tech" look with this model. I think the faux-F1 interior is kind of cool looking, but it polarized some people. The one thing that bugs me that some owners felt the need to put that crappy adhesive wood/carbon-fiber trim all over the car, and it looks terribly mis-matched on every interior surface of the car, especially since it peels away and fades after 3 years, making it look like a worn-out 3M test subject.
Lexus leather is a sore spot with me; it requires tender loving care, and it typically isn't the same quality or tactile feel of the German and British-car leather. Most 1st-gen IS 300s have a perforated sport-cloth/pseudo-suede with leather inserts that don't have this problem.
Stock CD players were nuisances on this car; it was the first Lexus model to feature the in-dash 6-disk players (from Panasonic/Pioneer). They would get hot, overheat, and occasionally fail to play burned disks, but much of this was actually caused by owners that put home-burnt CDs with sticker labels on them! Some cars can get away with this, but these radios will die if you try it: Use a Sharpie.
Avoid clouting a curb with the front end; control arms are hideously expensive, you might as well file an insurance claim, because you'll be out $1200-1500 in repairs easily with a decent enough strike. Look for missing splashguards and fender-well trim to tell how much abuse it's received from the owner and shady repair shops.
Yes, that chrome-like shifter knob is very hot in the summer time. Close the sun roof cover when parked!
Exterior fit and finish is top-notch, no complaints there, although some cars had deck lid lip spoilers installed at the factory, others did not. Take a close look, because any of the aftermarket ones are naturally suspect.
There's lots of older owners that bought this car, although you're more likely to get an automatic that way. The bonus is that the car was likely taken care of and is low-mileage.