EHAA
1 of a suit: 13+, 4 card majors. Unlimited. Responses are 6+, and Gorenish. Very few (or no) conventions.
1NT: 10-12
2 of a suit: 6-12, 5+ cards, may be any 5 card suit, including a 6 count with a 65432 suit at unfavorable. New suits are NF, 2NT and a raise to 3 are invitational. Jump shifts are GF.
Very aggressive, simple system. 2 bids are hard to handle for the opps, but game and slams are difficult to bid.
Fantoni-Nunes
1 of a suit: 14+ unbalanced, 15+ balanced, 5 card majors, 4 card 1D (unbalanced, usually 5+), 1C is 2+ and contains balanced hands with no 5cM outside of the NT ranges. Unlimited and forcing. 1 level responses are 1-9, 2 level responses are 10+ and GF. 2C (or 1C-2D) is a catchall GF: other 2/1s are 5+ cards. 3 level responses are 5-5 GF.
1NT: 12-14
2 of a suit: 10(9)-13, 5+ cards, unbalanced, may be any 5 card suit. 2m may be 4441. Relay continuations.
An aggressive, sophisticated system.
Chicken EHAA (my system)
1 of a suit: 13+ unbalanced, 14+ balanced, 5 card majors. Unlimited. Responses are 4+, and basically Standard American. Some conventions (NMF, 4sf, splinters, etc.), but not many. Invite with 9-10, drive to game with 11.
1NT: 10-13, includes most 5422s 10-bad 13, unless a strong suit, where we open 2X.
2 of a suit: 9(8)-12, 5+ cards, may be any 5 card suit, though we may pass 9 and 10 counts with bad 5 card suits when vulnerable. New suits are NF at the 2 level, GF at the 3 level. 2NT is a GF distributional inquiry (natural rebid). A raise to 3 is invitational, with 2+ trumps.
Although inspired by Fantoni-Nunes, this is actually much closer to EHAA (we play 5 card majors vs 4 because that is what we are used to - 4 card majors would work fine). The biggest difference is the tighter range on the 2 bids, which allow a response structure which is much better for game and slam bidding than the EHAA structure. It also provides for some nice penalty doubles

Are you playing anything like these systems?
Peter