Popular breeds..

It depends what level of riding it is you want to do. Most horses in the higher levels have tb lines or tb in them because of the endurance and because they were bred to run.
I've seen all sorts of breeds and crosses in all 3 phases of eventing. I think it just depends on how athletic the horse is really and how it's trained and prepared for the level it's competing at. I know of a horse that has conformation that's worst than the neighbors donkey and he's doing Prix Saint George!

Needless to say breed isn't always as much of a factor as training and the horse's ability.

I competed with two horses in Australia, one was an Irish Sporthorse and the other an OTTB. Both were awesome and though my Irish ended up retiring early (only because my family preferred he stay at the farm) my OTTB went on to the next owner and on to the next level.

I event (beginner levels so far) with my Paint/QH But I do see mainly lighter draft crosses like MIEventer mentioned at the events I attend. You can really event on any horse at the lower levels, like some have mentioned, but as you go higher you do need a certain type of horse -- not necessarily BREED, but horse...I only say that because there are some horses I've known that were of a certain breed but had characteristics of another breed...

Case in point my QH who has an Arab face for whatever reason, even though she has NO Arab in her bloodlines! Lol

Blue has an arab face and she is a registered APH!

I love TB/welsh crosses, althoughI see them in the hunter ring. Fatastic little horses!

I like those too ! The mare I evented for 2yrs was a tb/welsh cob cross, she was amazingly athletic & SUPER smart ! She had never evented before I rode her [she was a fox hunter] but I took her training & she would jump the moon if you asked her to. She had a lot of wild knee action though, which made her very handy over fences but not too well liked in dressage

Small world!

I know right!

My guy is mostly arab and doesnt have an arab head at all. Find a horse suited to eventing seems more about physical ability and the heart to do it vs. the breed.

My apologies for the delay...but I've been away!

Like I said...Lusitanos DO work very well in most disciplines...they excell at dressage and "Equitação de trabalho"...but there are a few examples like Novilheiro that was 7x times european champion jumping and won many competitions in Eventing (this is the one I know better).

Some pictures to share (the first two pictures are from Novinheiro and the last one from Preferido):