JLNY thanks for the input, it is most valuable. I have been considering new versus used, and personally would prefer going with an analog oscilloscope. Just finding a good one indeed will take time, patience and careful screening. I have worked with Tektronix many years ago on a professional basis and have always been impressed with their quality.
And yes you would do me a favour by giving your recommendations from experience.
My pleasure. I tend to work more on analog applications, but I also have some experience with microcontrollers, so my experience can hopefully shed some light on what you might look for. If you have professional experience, then you probably have a reasonably good sense of what you want already.
My first oscilloscope was a Hitachi V-1100 (also sometimes called a V-1100A, although I have never heard of a V-1100B), an analog scope with 4 channels @ 100MHz. It has two channels with full functionality, and two with limited voltage sensitivity settings, and also has an on-screen display with a frequency counter and voltage/time markers. It seems to be roughly equivalent to the more common Tektronix 2200/2400-series analog scopes, but similar to the TDS series, the 2200/2400-series tend to have power supply problems. Avoid any listings that do not show the screen turned on or that show the screen being out of focus, as this tends to be a sign of failing capacitors. The main feature these lack is sample holding or storage of any kind, which can be a really nice feature to have for digital applications where you need to capture one-time signals. I got my V-1100 for about $100 about 7 years ago, and it is still working fine.
In addition to the TDS 340 I got recently, I have used several TDS-series scopes over the years, including some of the newer color 4-channel ones. They have a really nice balance of features and a good interface, and the sampling for one-shot signals is really excellent, but they can be a real gamble on Ebay due to the aforementioned capacitor problems. If you decided to look at any of those, I would be very careful to only go for listings that show the unit on and working, preferably with an image of the "self-test passed" message on startup. I got burned a while back on an "untested" TDS 684C that was DOA.
The HP alternative to the TDS line is the HP 54000 line. It has quite a few entries, some of which are more digital-focused and others which are more like traditional analog scopes, so you can look around at what's out there. A co-worker of mine has one (a 54600B, IIRC), and he has had no problems with it as far as I know. AFAIK, I think they have a slightly better track record for reliability, but the HP name can sometimes raise the price.
The only other scope I have used, and which I don't recommend AT ALL, was an old boat-anchor of an HP 140A, which is actually a general-purpose display mainframe that can take various kinds of plug-ins for either oscilloscopes, spectrum analyzers, Time-Domain Reflectometers, and several others. I bought it so that I could use the scope plugins to calibrate the display unit in my spectrum analyzer, and as a spare display mainframe in case my main one breaks down (the HP 140/141 mainframes are very cranky, old units, so they tend to pop fuses and transistors in the power supply from time to time). The massive round display is actually surprisingly nice to look at once you calibrate the power supply and the focusing, but the limited frequency range will likely exclude most "boat-anchors" from your search. I have never actually tried using it in my 141T storage mainframe to see how well it works as an analog storage scope, but if my experience with the spectrum analyzer is anything to go by, analog storage can be extremely finicky to get just right so that the signal "sticks" without being too bright and blooming out the screen.
I'm sure others on this forum can give their reference points on what scopes they have used. Tektronix and HP tend to get a lot of attention, but I would be interested to hear what experiences folks have had with the more "off-brand" scopes like my Hitachi.