There are a LOT of good choices...it is getting harder & harder to make a dud... don't make me pick one for you
Even in my biggish room, with my 5W SE, the FE127eN gets the most time hooked up (not necessarily the same one (althou it is currently an experimentak set of FE108eS in Aiko). If i has real corners the Frugel-Horns would get more use, and i do have to free up a set of 126 for the Ron Horns now that i can get them up against the wall, Everytome i hook up a set of bigger drivers i'm not long before the little ones are back*, because i miss the midrange (so i'm working on some helper woofers (more to take some of the load off the 127s than for the bass) -- but not to fast, i probably won't know i'm missing them till i get used to them being there). At some point Harvey or Gabriel (or Gabriele, the curvy version), might well mitigate the need for even that.
*(except for the Visaton B200 -- the big baffles are the culprits there)
The discovery of how really good the FF85k is (and the arrival of a proto of a new 2" Aluminum cone mid-tweeter) will have us playing with FAST. A version of MJK baffle, and i'm playing woth the idea of MTM with FF85k and 350 Hz XO. Curvy Chang is also in the schedule -- i need something to work out my series XO ideas with the 207 & the FT17.
Here is a set of steps to help you choose... 1st a general guidline on pros and cons of driver sizes
Choosing a FR means you have to choose your tradeoffs... i'll just tick off a general ones ...
1/ bigger drivers tend to be more efficient than little ones (which mean they play louder with a small amp)
2/ smaller drivers usually have better mids & tops.
3/ bigger drivers go lower & tend to be able to do dynamics better
4/ small drivers usually go in smaller boxes, with higher WAF, and lower cost to build
5/ bigger drivers tend to cost more (and i haven't meet a driver i can't improve)
6/ and a corollary to 5... a modded small driver for the price of a similar priced large driver will usually have more finese. (disclousure: i sell modded drivers)
Now goinf thru the myriad of designs, toss the ones that won't work due to your room, cost, size, aesthetics, your amp(s), too hard to build, whim (ie no corners, BIBs or Frugel-Horns won't work to their best). Take what remains and pick the ones you like the best. Now take the short list to your significant other and ask them which one.
The other approach (more or less the one we use here) ... just start working your way thru them all (then it isn't which one to build, but which one to build next)
dave