I am surprised there weren't more responses given the general level of teklust around here... My current wish list looks like this:
7834 or 7844 (storage or dual beam, hard to choose),
7A19 or 7A24
7A26
7A42
7B80 or 7B85
specialty stuff: 7A11, 7A22, 7CT1N, 7L5 w/ opt 30, 7L12
I'm not a big fan of the 7834, especially the older ones with the 154-0745-00 CRT, which I find murky and ugly. If you must have storage, the 7934 is much better. Any storage mainframe will be greatly inferior to non-storage in trace brightness.
(Note: Plugins that really benefit from storage are the 7CT1N and the 7L12/7L13, but it makes more sense to get a 7613 to use with them.)
The 7844 is OK, but don't expect to get much out of the dual beamness. (I usually just put the readout on one of the beams, so it doesn't make the trace flicker.) Do not buy a 7844 with the P11 (eyehurt blue) CRT.
Try to get 7A29s instead of 7A19s or 7A24s... instead of unobtainium fuses, they have resettable input protection.
7B80 and 7B85 form a set. Also consider the amazing 7B92A.
Instead of a 7A11, look for a P6201 or P6202.
The 7L spectrum analyzers are really, really hard to repair and maintain.